Systems and methods for creating feedstock lines for additive manufacturing of an object

ABSTRACT

A feedstock line comprises elongate filaments, a resin, and a full-length optical waveguide, comprising a full-length optical core. The full-length optical waveguide is configured such that when electromagnetic radiation enters the full-length optical core via at least one of a first full-length-optical-core end face, a second full-length-optical-core end face, or a full-length peripheral surface that extends between the first full-length-optical-core end face and the second full-length-optical-core end face, at least a portion of the electromagnetic radiation exits the full-length optical core via the full-length peripheral surface to irradiate, in an interior volume of the feedstock line, the resin that, due at least in part to the elongate filaments, is not directly accessible to the electromagnetic radiation, incident on the exterior surface of the feedstock line.

FIELD

The present disclosure relates to additive manufacturing.

BACKGROUND

A 3D printing process may use a feedstock material, extruded from aprint head, to additively manufacture a part by layering the feedstockmaterial. The feedstock material may comprise a polymer and reinforcingfibers, such as carbon fibers, which are opaque to visible andultra-violet light. When the polymer in the feedstock material is aphotopolymer, a source of curing energy may be directed at the feedstockmaterial, dispensed by the print head, to solidify the feedstockmaterial. However, when the reinforcing fibers are opaque to the curingenergy, they cast shadows and prevent the curing energy, originatingdirectly from the source of curing energy, from irradiating and curingthe photopolymer in the shadows.

SUMMARY

Accordingly, apparatuses and methods, intended to address at least theabove-identified concerns, would find utility.

The following is a non-exhaustive list of examples, which may or may notbe claimed, of the subject matter according to the invention.

One example of the subject matter according to the invention relates toa feedstock line for additive manufacturing of an object. The feedstockline has a feedstock-line length and an exterior surface, defining aninterior volume of the feedstock line. The feedstock line compriseselongate filaments, a resin, and at least one full-length opticalwaveguide. The elongate filaments extend along at least a portion of thefeedstock-line length. The resin covers the elongate filaments. At leastthe one full-length optical waveguide extends along all of thefeedstock-line length. At least the one full-length optical waveguide iscovered by the resin and is interspersed among the elongate filaments.At least the one full-length optical waveguide comprises a full-lengthoptical core. The full-length optical core comprises a firstfull-length-optical-core end face, a second full-length-optical-core endface, opposite the first full-length-optical-core end face, and afull-length peripheral surface, extending between the firstfull-length-optical-core end face and the secondfull-length-optical-core end face. At least the one full-length opticalwaveguide is configured such that when electromagnetic radiation entersthe full-length optical core via at least one of the firstfull-length-optical-core end face, the second full-length-optical-coreend face, or the full-length peripheral surface, at least a portion ofthe electromagnetic radiation exits the full-length optical core via thefull-length peripheral surface to irradiate, in the interior volume ofthe feedstock line, the resin that, due at least in part to the elongatefilaments, is not directly accessible to the electromagnetic radiation,incident on the exterior surface of the feedstock line.

Inclusion of at least one full-length optical waveguide in the feedstockline facilitates penetration of the electromagnetic radiation into theinterior volume of the feedstock line for irradiation of the resin,despite regions of the resin being in the shadows of the elongatefilaments cast by the direct (i.e., line-of-sight) application of theelectromagnetic radiation. In other words, even when the electromagneticradiation is shielded from directly reaching all regions of the resin,at least one full-length optical waveguide will receive theelectromagnetic radiation via one or more of its first end face, itssecond end face, or its peripheral surface, and disperse theelectromagnetic radiation via at least its peripheral surface toindirectly reach regions of the resin. As a result, the feedstock linemay be more easily cured with the electromagnetic radiation, may be moreevenly cured with the electromagnetic radiation, may be more thoroughlycured with the electromagnetic radiation, and/or may be more quicklycured with the electromagnetic radiation. This configuration offeedstock line is particularly well suited for additive manufacturing ofthe fused filament fabrication variety, in which a feedstock line isdispensed by a print head, or nozzle, and a source of curing energy(e.g., electromagnetic radiation) directs the curing energy at thefeedstock line as it is being dispensed to cure the resin in situ.

Another example of the subject matter according to the invention relatesto a system for creating a feedstock line for additive manufacturing ofan object. The feedstock line has a feedstock-line length. The systemcomprises a prepreg-tow supply, a full-length-optical-waveguide supply,a combiner, and at least one heater. The prepreg-tow supply isconfigured to dispense a precursor prepreg tow that comprises elongatefilaments and resin, covering the elongate filaments. The prepreg-towseparator is configured to separate the precursor prepreg tow, dispensedfrom the prepreg-tow supply, into individual ones of the elongatefilaments, at least partially covered with the resin, or into subsets ofthe elongate filaments, at least partially covered with the resin. Eachof the subsets comprises a plurality of the elongate filaments. Thefull-length-optical-waveguide supply is configured to dispense at leastone full-length optical waveguide. The combiner is configured to combinethe individual ones of the elongate filaments, originating from theprepreg-tow separator, and at least the one full-length opticalwaveguide, dispensed by the full-length-optical-waveguide supply, or thesubsets of the elongate filaments, originating from the prepreg-towseparator, and at least the one full-length optical waveguide, dispensedby the full-length-optical-waveguide supply, into a derivative prepregtow so that each of the elongate filaments and at least the onefull-length optical waveguide extend along all of the feedstock-linelength and at least the one full-length optical waveguide isinterspersed among the elongate filaments. At least the one heater isconfigured to heat at least one of (i) the resin in the precursorprepreg tow, dispensed from the prepreg-tow supply, to a first thresholdtemperature to facilitate separation of the precursor prepreg tow by theprepreg-tow separator into the individual ones of the elongate filamentsor into the subsets of the elongate filaments; (ii) the resin that atleast partially covers the individual ones of the elongate filaments orthe subsets of the elongate filaments, originating from the prepreg-towseparator, to a second threshold temperature to cause wet-out of atleast the one full-length optical waveguide and the individual ones ofthe elongate filaments or of at least the one full-length opticalwaveguide and the subsets of the elongate filaments in the derivativeprepreg tow by the resin; or (iii) the resin that at least partiallycovers the elongate filaments in the derivative prepreg tow, originatingfrom the combiner, to a third threshold temperature to cause wet-out ofat least the one full-length optical waveguide and the elongatefilaments in the derivative prepreg tow by the resin.

Creating the feedstock line from the precursor prepreg tow permits theuse of off-the-shelf prepreg reinforcement fiber tows. The prepreg-towseparator separates the precursor prepreg tow into individual ones ofthe elongate filaments that are at least partially covered with resin orinto subsets of elongate filaments that are at least partially coveredwith resin, so that at least the one full-length optical waveguide maybe operatively interspersed with the elongate filaments. The combinerthen combines the elongate filaments and at least the one full-lengthoptical waveguide, together with the resin, into the derivative prepregtow to ultimately become the feedstock line. At least the one heaterheats the resin to facilitate one or both of separation of the precursorprepreg two or wetting-out of the elongate filaments and at least theone full-length optical waveguide in the derivative prepreg tow.

Yet another example of the subject matter according to the inventionrelates to a method of creating a feedstock line for additivemanufacturing of an object. The feedstock line has a feedstock-linelength. The method comprises separating a precursor prepreg tow,comprising elongate filaments and resin, covering the elongatefilaments, into individual ones of the elongate filaments, at leastpartially covered with the resin, or into subsets of the elongatefilaments, at least partially covered with the resin. Each of thesubsets comprises a plurality of the elongate filaments. The method alsocomprises combining the individual ones of the elongate filaments, atleast partially covered with the resin, and at least one full-lengthoptical waveguide or the subsets of the elongate filaments, at leastpartially covered with the resin, and at least the one full-lengthoptical waveguide into a derivative prepreg tow so that each of theelongate filaments and at least the one full-length optical waveguideextend along all of the feedstock-line length and at least the onefull-length optical waveguide is interspersed among the elongatefilaments. The method further comprises heating at least one of (i) theresin in the precursor prepreg tow prior to separating the precursorprepreg tow into the individual ones of the elongate filaments, at leastpartially covered with the resin, or into the subsets of the elongatefilaments, at least partially covered with the resin, to a firstthreshold temperature to facilitate separating the precursor prepregtow; (ii) the resin, at least partially covering the individual ones ofthe elongate filaments or the subsets of the elongate filamentsfollowing separating the precursor prepreg tow into the individual onesof the elongate filaments, at least partially covered with the resin, orinto the subsets of the elongate filaments, at least partially coveredwith the resin, and prior to combining the individual ones of theelongate filaments, at least partially covered with the resin, and atleast the one full-length optical waveguide or the subsets of theelongate filaments, at least partially covered with the resin, and atleast the one full-length optical waveguide into the derivative prepregtow, to a second threshold temperature to cause wet-out of at least theone full-length optical waveguide and the elongate filaments in thederivative prepreg tow by the resin; or (iii) the resin, at leastpartially covering the elongate filaments in the derivative prepreg tow,to a third threshold temperature to cause wet-out of at least the onefull-length optical waveguide and the elongate filaments in thederivative prepreg tow by the resin.

Creating the feedstock line from the precursor prepreg tow permits theuse of off-the-shelf prepreg reinforcement fiber tows. By separating theprecursor prepreg tow into individual ones of the elongate filaments orinto subsets of elongate filaments, at least the one full-length opticalwaveguide may be operatively interspersed with the elongate filaments.Heating the resin facilitates one or both of separation of the precursorprepreg tow or wetting-out of the elongate filaments and at least theone full-length optical waveguide in the derivative prepreg tow.

BRIEF DESCRIPTION OF THE DRAWINGS

Having thus described one or more examples of the invention in generalterms, reference will now be made to the accompanying drawings, whichare not necessarily drawn to scale, and wherein like referencecharacters designate the same or similar parts throughout the severalviews, and wherein:

FIG. 1 is a block diagram, schematically representing a feedstock linefor additive manufacturing of an object, according to one or moreexamples of the present disclosure;

FIG. 2 is a block diagram, schematically representing a system forcreating a feedstock line for additive manufacturing of an object,according to one or more examples of the present disclosure;

FIG. 3 is a block diagram, schematically representing an opticalwaveguide, according to one or more examples of the present disclosure;

FIG. 4 is a schematic representation of a feedstock line of FIG. 1,according to one or more examples of the present disclosure;

FIG. 5 is a schematic representation of a feedstock line of FIG. 1,according to one or more examples of the present disclosure;

FIG. 6 is a schematic representation of a feedstock line of FIG. 1,according to one or more examples of the present disclosure;

FIG. 7 is a schematic representation of a feedstock line of FIG. 1,according to one or more examples of the present disclosure;

FIG. 8 is a schematic representation of an optical fiber that may bemodified to create an optical waveguide of FIG. 3, according to one ormore examples of the present disclosure;

FIG. 9 is a schematic representation of an optical waveguide, accordingto one or more examples of the present disclosure;

FIG. 10 is a schematic representation of an optical waveguide, accordingto one or more examples of the present disclosure;

FIG. 11 is a schematic representation of an optical waveguide, accordingto one or more examples of the present disclosure;

FIG. 12 is a schematic representation of an optical waveguide, accordingto one or more examples of the present disclosure;

FIG. 13 is a schematic representation of a system of FIG. 2, accordingto one or more examples of the present disclosure;

FIG. 14 is a schematic representation of a system of FIG. 2, accordingto one or more examples of the present disclosure;

FIG. 15 is a schematic representation of an optical direction-modifyingparticle, according to one or more examples of the present disclosure;

FIG. 16 is a schematic representation of an optical direction-modifyingparticle, according to one or more examples of the present disclosure;

FIG. 17 is a schematic representation of an optical direction-modifyingparticle, according to one or more examples of the present disclosure;

FIG. 18 is a block diagram of a method of creating a feedstock line foradditive manufacturing of an object, according to one or more examplesof the present disclosure;

FIG. 19 is a block diagram of a method of modifying an optical fiber tocreate an optical waveguide, according to one or more examples of thepresent disclosure;

FIG. 20 is a block diagram of a method of modifying an optical fiber tocreate an optical waveguide, according to one or more examples of thepresent disclosure;

FIG. 21 is a block diagram of a method of modifying an optical fiber tocreate an optical waveguide, according to one or more examples of thepresent disclosure;

FIG. 22 is a block diagram of aircraft production and servicemethodology; and

FIG. 23 is a schematic illustration of an aircraft.

DESCRIPTION

In FIGS. 1-3, referred to above, solid lines, if any, connecting variouselements and/or components may represent mechanical, electrical, fluid,optical, electromagnetic and other couplings and/or combinationsthereof. As used herein, “coupled” means associated directly as well asindirectly. For example, a member A may be directly associated with amember B, or may be indirectly associated therewith, e.g., via anothermember C. It will be understood that not all relationships among thevarious disclosed elements are necessarily represented. Accordingly,couplings other than those depicted in the block diagrams may alsoexist. Dashed lines, if any, connecting blocks designating the variouselements and/or components represent couplings similar in function andpurpose to those represented by solid lines; however, couplingsrepresented by the dashed lines may either be selectively provided ormay relate to alternative examples of the present disclosure. Likewise,elements and/or components, if any, represented with dashed lines,indicate alternative examples of the present disclosure. One or moreelements shown in solid and/or dashed lines may be omitted from aparticular example without departing from the scope of the presentdisclosure. Environmental elements, if any, are represented with dottedlines. Virtual imaginary elements may also be shown for clarity. Thoseskilled in the art will appreciate that some of the features illustratedin FIGS. 1-3 may be combined in various ways without the need to includeother features described in FIGS. 1-3, other drawing figures, and/or theaccompanying disclosure, even though such combination or combinationsare not explicitly illustrated herein. Similarly, additional featuresnot limited to the examples presented, may be combined with some or allof the features shown and described herein.

In FIGS. 18-22, referred to above, the blocks may represent operationsand/or portions thereof, and lines connecting the various blocks do notimply any particular order or dependency of the operations or portionsthereof. Blocks represented by dashed lines indicate alternativeoperations and/or portions thereof. Dashed lines, if any, connecting thevarious blocks represent alternative dependencies of the operations orportions thereof. It will be understood that not all dependencies amongthe various disclosed operations are necessarily represented. FIGS.18-22 and the accompanying disclosure describing the operations of themethods set forth herein should not be interpreted as necessarilydetermining a sequence in which the operations are to be performed.Rather, although one illustrative order is indicated, it is to beunderstood that the sequence of the operations may be modified whenappropriate. Accordingly, certain operations may be performed in adifferent order or simultaneously. Additionally, those skilled in theart will appreciate that not all operations described need be performed.

In the following description, numerous specific details are set forth toprovide a thorough understanding of the disclosed concepts, which may bepracticed without some or all of these particulars. In other instances,details of known devices and/or processes have been omitted to avoidunnecessarily obscuring the disclosure. While some concepts will bedescribed in conjunction with specific examples, it will be understoodthat these examples are not intended to be limiting.

Unless otherwise indicated, the terms “first,” “second,” etc. are usedherein merely as labels, and are not intended to impose ordinal,positional, or hierarchical requirements on the items to which theseterms refer. Moreover, reference to, e.g., a “second” item does notrequire or preclude the existence of, e.g., a “first” or lower-numbereditem, and/or, e.g., a “third” or higher-numbered item.

Reference herein to “one example” means that one or more feature,structure, or characteristic described in connection with the example isincluded in at least one implementation. The phrase “one example” invarious places in the specification may or may not be referring to thesame example.

As used herein, a system, apparatus, structure, article, element,component, or hardware “configured to” perform a specified function isindeed capable of performing the specified function without anyalteration, rather than merely having potential to perform the specifiedfunction after further modification. In other words, the system,apparatus, structure, article, element, component, or hardware“configured to” perform a specified function is specifically selected,created, implemented, utilized, programmed, and/or designed for thepurpose of performing the specified function. As used herein,“configured to” denotes existing characteristics of a system, apparatus,structure, article, element, component, or hardware which enable thesystem, apparatus, structure, article, element, component, or hardwareto perform the specified function without further modification. Forpurposes of this disclosure, a system, apparatus, structure, article,element, component, or hardware described as being “configured to”perform a particular function may additionally or alternatively bedescribed as being “adapted to” and/or as being “operative to” performthat function.

Illustrative, non-exhaustive examples, which may or may not be claimed,of the subject matter according the present disclosure are providedbelow.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 4-7 and9-12, feedstock line 100 for additive manufacturing of object 136 isdisclosed. Feedstock line 100 has a feedstock-line length and exteriorsurface 180, defining interior volume 182 of feedstock line 100.Feedstock line 100 comprises elongate filaments 104, resin 124, and atleast one full-length optical waveguide 102. Elongate filaments 104extend along at least a portion of the feedstock-line length. Resin 124covers elongate filaments 104. At least one full-length opticalwaveguide 102 extends along all of the feedstock-line length. At leastone full-length optical waveguide 102 is covered by resin 124 and isinterspersed among elongate filaments 104. At least one full-lengthoptical waveguide 102 comprises full-length optical core 110.Full-length optical core 110 comprises first full-length-optical-coreend face 112, second full-length-optical-core end face 114, oppositefirst full-length-optical-core end face 112, and full-length peripheralsurface 116, extending between first full-length-optical-core end face112 and second full-length-optical-core end face 114. At least onefull-length optical waveguide 102 is configured such that whenelectromagnetic radiation 118 enters full-length optical core 110 via atleast one of first full-length-optical-core end face 112, secondfull-length-optical-core end face 114, or full-length peripheral surface116, at least a portion of electromagnetic radiation 118 exitsfull-length optical core 110 via full-length peripheral surface 116 toirradiate, in interior volume 182 of feedstock line 100, resin 124 that,due at least in part to elongate filaments 104, is not directlyaccessible to electromagnetic radiation 118, incident on exteriorsurface 180 of feedstock line 100. The preceding subject matter of thisparagraph characterizes example 1 of the present disclosure.

Inclusion of at least one full-length optical waveguide 102 in feedstockline 100 facilitates penetration of electromagnetic radiation 118 intointerior volume 182 of feedstock line 100 for irradiation of resin 124,despite regions of resin 124 being in the shadows of elongate filaments104 cast by the direct (i.e., line-of-sight) application ofelectromagnetic radiation 118. In other words, even when electromagneticradiation 118 is shielded from directly reaching all regions of resin124, at least one full-length optical waveguide 102 will receiveelectromagnetic radiation 118 via one or more of its firstfull-length-optical-core end face 112, its secondfull-length-optical-core end face 114, or its full-length peripheralsurface 116, and disperse electromagnetic radiation 118 via at least itsfull-length peripheral surface 116 to indirectly reach regions of resin124. As a result, feedstock line 100 may be more easily cured withelectromagnetic radiation 118, may be more evenly cured withelectromagnetic radiation 118, may be more thoroughly cured withelectromagnetic radiation 118, and/or may be more quickly cured withelectromagnetic radiation 118. This configuration of feedstock line 100is particularly well suited for additive manufacturing of the fusedfilament fabrication variety, in which feedstock line 100 is dispensedby a print head, or nozzle, and a source of curing energy (e.g.,electromagnetic radiation 118) directs the curing energy at feedstockline 100 as it is being dispensed to cure resin 124 in situ.

Elongate filaments 104 additionally or alternatively may be described asreinforcement filaments or fibers, and may be constructed of anysuitable material, illustrative and non-exclusive examples of whichinclude (but are not limited to) fibers, carbon fibers, glass fibers,synthetic organic fibers, aramid fibers, natural fibers, wood fibers,boron fibers, silicon-carbide fibers, optical fibers, fiber bundles,fiber tows, fiber weaves, wires, metal wires, conductive wires, and wirebundles. Feedstock line 100 may include a single configuration, or type,of elongate filaments 104 or may include more than one configuration, ortype, of elongate filaments 104. In some examples, elongate filaments104 may individually and collectively extend for the entire, orsubstantially the entire, feedstock-line length, and thus may bedescribed as continuous elongate filaments or as full-length elongatefilaments. Additionally or alternatively elongate filaments 104 mayindividually extend for only a portion of the feedstock-line length, andthus may be described as partial-length elongate filaments ornon-continuous elongate filaments. Examples of partial-length elongatefilaments include (but are not limited to) so-called chopped fibers.

Resin 124 may include any suitable material that is configured to becured, or hardened, as a result of cross-linking of polymer chains, suchas responsive to an application of electromagnetic radiation 118. Forexample, electromagnetic radiation 118, or curing energy, may compriseone or more of ultraviolet light, visible light, infrared light, x-rays,electron beams, and microwaves, and resin 124 may take the form of oneor more of a polymer, a resin, a thermoplastic, a thermoset, aphotopolymer, an ultra-violet photopolymer, a visible-lightphotopolymer, an infrared-light photopolymer, and an x-ray photopolymer.As used herein, a photopolymer is a polymer that is configured to becured in the presence of light, such as one or more of ultra-violetlight, visible-light, infrared-light, and x-rays. However, as discussed,inclusion of at least one full-length optical wave guide 102 infeedstock line 100 specifically facilitates the penetration ofelectromagnetic radiation 118 into the shadows of elongate filaments104, and thus electromagnetic radiation 118 typically will be of awavelength that does not penetrate elongate filaments 104, and resin 124typically will be a photopolymer.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 4-7,elongate filaments 104 are opaque to electromagnetic radiation 118. Thepreceding subject matter of this paragraph characterizes example 2 ofthe present disclosure, wherein example 2 also includes the subjectmatter according to example 1, above.

Elongate filaments 104 typically will be selected for strengthproperties and not for light-transmissivity properties. For example,carbon fibers are often used in fiber-reinforced composite structures,and carbon fibers are opaque to ultra-violet and visible light.Accordingly, elongate filaments 104 that are opaque to electromagneticradiation 118 are well suited for inclusion in feedstock line 100, as atleast one full-length optical waveguide 102 operatively will receiveelectromagnetic radiation 118 and disperse it into the shadows ofelongate filaments 104.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 4-7,feedstock line 100 is configured such that when electromagneticradiation 118 enters interior volume 182 of feedstock line 100 viaexterior surface 180 of feedstock line 100, electromagnetic radiation118 enters at least one full-length optical waveguide 102 via at leastone of full-length peripheral surface 116, firstfull-length-optical-core end face 112, or secondfull-length-optical-core end face 114 of full-length optical core 110 ofat least one full-length optical waveguide 102. The preceding subjectmatter of this paragraph characterizes example 3 of the presentdisclosure, wherein example 3 also includes the subject matter accordingto example 1 or 2, above.

In other words, in some examples of feedstock line 100, at least onefull-length optical waveguide 102 is positioned within interior volume182 of feedstock line 100 such that at least one of full-lengthperipheral surface 116, first full-length-optical-core end face 112, orsecond full-length-optical-core end face 114 is within the line of sightof electromagnetic radiation 118 to receive electromagnetic radiation118 directed to exterior surface 180 of feedstock line 100 and thendisperse electromagnetic radiation 118 into the shadows of elongatefilaments 104. For example, at least one of full-length peripheralsurface 116, first full-length-optical-core end face 112, or secondfull-length-optical-core end face 114 may be adjacent to exteriorsurface 180 of feedstock line 100.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 4-7 and9-12, at least one full-length optical waveguide 102 is configured suchthat when electromagnetic radiation 118 enters firstfull-length-optical-core end face 112 of full-length optical core 110,an initial portion of electromagnetic radiation 118 exits full-lengthoptical core 110 via full-length peripheral surface 116 and a finalportion of electromagnetic radiation 118, remaining in full-lengthoptical core 110 after the initial portion of electromagnetic radiation118 exits full-length optical core 110, exits full-length optical core110 via second full-length-optical-core end face 114. The precedingsubject matter of this paragraph characterizes example 4 of the presentdisclosure, wherein example 4 also includes the subject matter accordingto any one of examples 1 to 3, above.

In other words, in some examples of feedstock line 100, ifelectromagnetic radiation 118 enters first full-length-optical-core endface 112, it will exit both full-length peripheral surface 116 andsecond full-length-optical-core end face 114, as opposed, for example,to electromagnetic radiation 118 being fully emitted via full-lengthperipheral surface 116. Such examples of feedstock line 100 are wellsuited for additive manufacturing systems and methods in whichelectromagnetic radiation 118 is directed at firstfull-length-optical-core end face 112 as feedstock line 100 is beingconstructed and as object 136 is being manufactured. That is, anadditive manufacturing system may be configured to construct feedstockline 100 while object 136 is being manufactured from feedstock line 100,and while electromagnetic radiation 118 is entering firstfull-length-optical-core end face 112. Because electromagnetic radiation118 exits not only full-length peripheral surface 116, but also secondfull-length-optical-core end face 114, it is ensured that sufficientelectromagnetic radiation 118 travels the full length of at least onefull-length optical waveguide 102 to operatively cure resin 124 amongelongate filaments 104 within interior volume 182 of feedstock line 100.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 4-7 and9-12, at least one full-length optical waveguide 102 is configured suchthat the initial portion of electromagnetic radiation 118, which exitsfull-length optical core 110 via full-length peripheral surface 116 isgreater than or equal to the final portion of electromagnetic radiation118, which exits full-length optical core 110 via secondfull-length-optical-core end face 114. The preceding subject matter ofthis paragraph characterizes example 5 of the present disclosure,wherein example 5 also includes the subject matter according to example4, above.

In such configurations, it is ensured that a desired amount ofelectromagnetic radiation 118 exits full-length optical core 110 viafull-length peripheral surface 116 to operatively cure resin 124 amongelongate filaments 104 within interior volume 182 of feedstock line 100,when feedstock line 100 is utilized by an additive manufacturing systemor in an additive manufacturing method.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 4-7, atleast one full-length optical waveguide 102 is at least one of parallelto, generally parallel to, twisted with, woven with, or braided withelongate filaments 104. The preceding subject matter of this paragraphcharacterizes example 6 of the present disclosure, wherein example 6also includes the subject matter according to any one of examples 1 to5, above.

By at least one full-length optical waveguide 102 being generallyparallel to elongate filaments 104, the reinforcing properties ofelongate filaments 104 within feedstock line 100, and thus within object136 are not materially affected. By being twisted with, woven with, orbraided with elongate filaments 104, at least one full-length opticalwaveguide 102 is interspersed with elongate filaments 104 so thatelectromagnetic radiation 118, exiting at least one full-length opticalwaveguide 102, is delivered to regions of interior volume 182 that arein the shadows of elongated filaments 104.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 9-11,full-length optical core 110 has a full-length-optical-core refractiveindex. At least one full-length optical waveguide 102 further comprisesfull-length-optical-core cladding 154, at least partially coveringfull-length optical core 110. Full-length-optical-core cladding 154comprises at least first full-length-optical-core cladding resin 156,having a full-length-optical-core first-cladding-resin refractive index.Full-length-optical-core cladding 154 is non-uniform along at least onefull-length optical waveguide 102. Full-length-optical-core refractiveindex is greater than the full-length-optical-core first-cladding-resinrefractive index. The preceding subject matter of this paragraphcharacterizes example 7 of the present disclosure, wherein example 7also includes the subject matter according to any one of examples 1 to6, above.

By full-length-optical-core cladding 154 being non-uniform along thelength of the full-length optical waveguide, electromagnetic radiation118 is permitted to exit full-length optical core 110 via full-lengthperipheral surface 116. Moreover, by first full-length-optical-corecladding resin 156 having a refractive index that is less than that offull-length optical core 110, electromagnetic radiation 118, uponentering full-length optical core 110, is trapped within full-lengthoptical core 110 other than the regions where firstfull-length-optical-core cladding resin 156 is not present. As a result,at least one full-length optical waveguide 102 may be constructed toprovide a desired amount of electromagnetic radiation 118, exitingvarious positions along full-length peripheral surface 116, such as toensure a desired amount of electromagnetic radiation 118, penetratingthe shadows of elongate filaments 104.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 10 and11, full-length peripheral surface 116 hasfull-length-peripheral-surface regions 127 devoid of firstfull-length-optical-core cladding resin 156. Full-length-optical-corecladding 154 further comprises second full-length-optical-core claddingresin 158, having a full-length-optical-core second-cladding-resinrefractive index. Second full-length-optical-core cladding resin 158covers full-length-peripheral-surface regions 127 of full-lengthperipheral surface 116. The full-length-optical-coresecond-cladding-resin refractive index is greater than thefull-length-optical-core first-cladding-resin refractive index. Thepreceding subject matter of this paragraph characterizes example 8 ofthe present disclosure, wherein example 8 also includes the subjectmatter according to example 7, above.

By covering full-length-peripheral-surface regions 127 with secondfull-length-optical-core cladding resin 158, a desired refractive indexthereof may be selected to optimize how electromagnetic radiation 118exits full-length peripheral surface 116. Additionally or alternatively,with full-length-peripheral-surface regions 127 covered with secondfull-length-optical-core cladding resin 158, the integrity of firstfull-length-optical-core cladding resin 156 may be ensured, such that itdoes not peel or break off during storage of at least one full-lengthoptical waveguide 102 and during construction of feedstock line 100.

Referring generally to FIG. 1 and particularly to, e.g., FIG. 11, secondfull-length-optical-core cladding resin 158 also covers firstfull-length-optical-core cladding resin 156. The preceding subjectmatter of this paragraph characterizes example 9 of the presentdisclosure, wherein example 9 also includes the subject matter accordingto example 8, above.

Full-length optical waveguides according to example 9 may be more easilymanufactured, in that full-length optical core 110 with firstfull-length-optical-core cladding resin 156 simply may be fully coatedwith second full-length-optical-core cladding resin 158. Additionally oralternatively, the integrity of full-length optical waveguides may bemaintained during storage thereof and during construction of feedstockline 100.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 10 and11, resin 124 has a resin refractive index. The resin refractive indexis greater than the full-length-optical-core second-cladding-resinrefractive index. The preceding subject matter of this paragraphcharacterizes example 10 of the present disclosure, wherein example 10also includes the subject matter according to example 8 or 9, above.

Because second full-length-optical-core cladding resin 158 has arefractive index less than that of resin 124, electromagnetic radiation118 will be permitted to exit second full-length-optical-core claddingresin 158 to penetrate and cure resin 124 when feedstock line 100 isused to additively manufacture object 136.

Referring generally to FIG. 1 and particularly to, e.g., FIG. 12,full-length peripheral surface 116 has a surface roughness that isselected such that when electromagnetic radiation 118 enters full-lengthoptical core 110 via at least one of first full-length-optical-core endface 112, second full-length-optical-core end face 114, or full-lengthperipheral surface 116, at least a portion of electromagnetic radiation118 exits full-length optical core 110 via full-length peripheralsurface 116 to irradiate, in interior volume 182 of feedstock line 100,resin 124 that, due at least in part to elongate filaments 104, is notdirectly accessible to electromagnetic radiation 118, incident onexterior surface 180 of feedstock line 100. The preceding subject matterof this paragraph characterizes example 11 of the present disclosure,wherein example 11 also includes the subject matter according to any oneof examples 1 to 6, above.

Rather than relying on refractive-index properties of a cladding toensure desired dispersal of electromagnetic radiation 118 fromfull-length optical core 110 via full-length peripheral surface 116, thesurface roughness of full-length peripheral surface 116 is selected suchthat electromagnetic radiation 118 exits full-length optical core 110 atdesired amounts along the length of full-length peripheral surface 116.For example, the surface roughness may create regions of internalreflection of electromagnetic radiation 118 within full-length opticalcore 110 and may create regions where electromagnetic radiation 118 ispermitted to escape full-length optical core 110.

Referring generally to FIG. 1 and particularly to, e.g., FIG. 12, atleast one full-length optical waveguide 102 is devoid of any claddingthat covers full-length optical core 110. The preceding subject matterof this paragraph characterizes example 12 of the present disclosure,wherein example 12 also includes the subject matter according to example11, above.

Full-length optical waveguides without any cladding may be lessexpensive to manufacture than full-length optical waveguides withcladding. Additionally, the difference of refractive indexes between acladding and resin 124 need not be taken into account when selectingresin 124 for feedstock line 100.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 4-7, atleast one full-length optical waveguide 102 is a plurality offull-length optical waveguides, interspersed among elongate filaments104. The preceding subject matter of this paragraph characterizesexample 13 of the present disclosure, wherein example 13 also includesthe subject matter according to any one of examples 1 to 12, above.

By including a plurality of full-length optical waveguides, interspersedamong elongate filaments 104, such as among a bundle, or tow, ofelongate filaments, a desired penetration of electromagnetic radiation118 into the shadows of elongate filaments 104 is be ensured.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 4-7,elongate filaments 104 are at least one of twisted with, woven with, orbraided with the plurality of full-length optical waveguides. Thepreceding subject matter of this paragraph characterizes example 14 ofthe present disclosure, wherein example 14 also includes the subjectmatter according to example 13, above.

By being twisted with, woven with, or braided with elongate filaments104, the plurality of full-length optical waveguides is interspersedwith elongate filaments 104 so that electromagnetic radiation 118,exiting the full-length optical waveguides, is delivered to regions ofinterior volume 182 that are in the shadows of elongated filaments 104.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 5-7,9-12, and 15-17, feedstock line 100 further comprises optical directionmodifiers 123, each extending along only a portion of the feedstock-linelength. Optical direction modifiers 123 are covered by resin 124 and areinterspersed among elongate filaments 104. Each of optical directionmodifiers 123 has outer surface 184. Each of optical direction modifiers123 is configured such that when electromagnetic radiation 118 strikesouter surface 184 from a first direction, at least a portion ofelectromagnetic radiation 118 departs outer surface 184 in a seconddirection that is at an angle to the first direction to irradiate, ininterior volume 182 of feedstock line 100, resin 124 that, due at leastin part to elongate filaments 104, is not directly accessible toelectromagnetic radiation 118, incident on exterior surface 180 offeedstock line 100. The preceding subject matter of this paragraphcharacterizes example 15 of the present disclosure, wherein example 15also includes the subject matter according to any one of examples 1 to14, above.

Inclusion of optical direction modifiers 123, each extending only alonga portion of the feedstock line length, provides for further dispersionof electromagnetic radiation 118 within interior volume 182 forirradiation of resin 124 therein. Moreover, by being shorter thanfull-length optical waveguides, optical direction modifiers 123 may moreeasily extend among elongate filaments 104 of a bundle, or tow, ofelongate filaments 104. Not only may optical direction modifiers 123serve to disperse, or scatter, electromagnetic radiation 118 into theshadows of elongate filaments 104, but they also may serve to redirectelectromagnetic radiation 118 to at least one full-length opticalwaveguide 102 for penetration into the shadows of elongate filaments 104by at least one full-length optical waveguide 102.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 5, 7, and9-12, optical direction modifiers 123 comprise partial-length opticalwaveguides 122. Each of partial-length optical waveguides 122 comprisespartial-length optical core 138. Partial-length optical core 138 of eachof partial-length optical waveguides 122 comprises firstpartial-length-optical-core end face 140, secondpartial-length-optical-core end face 142, opposite firstpartial-length-optical-core end face 140, and partial-length peripheralsurface 144, extending between first partial-length-optical-core endface 140 and second partial-length-optical-core end face 142. Each ofpartial-length optical waveguides 122 is configured such that whenelectromagnetic radiation 118 enters partial-length optical core 138 viaat least one of first partial-length-optical-core end face 140, secondpartial-length-optical-core end face 142, or partial-length peripheralsurface 144, at least a portion of electromagnetic radiation 118 exitspartial-length optical core 138 via partial-length peripheral surface144 to irradiate, in interior volume 182 of feedstock line 100, resin124 that, due at least in part to elongate filaments 104, is notdirectly accessible to electromagnetic radiation 118, incident onexterior surface 180 of feedstock line 100. The preceding subject matterof this paragraph characterizes example 16 of the present disclosure,wherein example 16 also includes the subject matter according to example15, above.

That is, in some examples, optical direction modifiers 123 are similarin construction to full-length optical waveguides but are shorter inlength.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 5, 7, and9-12, feedstock line 100 is configured such that when electromagneticradiation 118 enters interior volume 182 of feedstock line 100 viaexterior surface 180 of feedstock line 100, electromagnetic radiation118 enters at least one of partial-length optical waveguides 122 via atleast one of partial-length peripheral surface 144, firstpartial-length-optical-core end face 140, or secondpartial-length-optical-core end face 142 of at least one ofpartial-length optical waveguides 122. The preceding subject matter ofthis paragraph characterizes example 17 of the present disclosure,wherein example 17 also includes the subject matter according to example16, above.

In other words, in some examples of feedstock line 100, partial-lengthoptical waveguides 122 are positioned within interior volume 182 offeedstock line 100 such that at least one of partial-length peripheralsurface 144, first partial-length-optical-core end face 140, or secondpartial-length-optical-core end face 142 is within the line of sight ofelectromagnetic radiation 118 to receive electromagnetic radiation 118directed to exterior surface 180 of feedstock line 100 and thendisperse, or scatter, electromagnetic radiation 118 within interiorvolume 182.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 5, 7, and9-11, partial-length optical core 138 has a partial-length-optical-corerefractive index. Each of partial-length optical waveguides 122 furthercomprises partial-length-optical-core cladding 160, at least partiallycovering partial-length optical core 138. Partial-length-optical-corecladding 160 comprises at least first partial-length-optical-corecladding resin 162, having a partial-length-optical-corefirst-cladding-resin refractive index. Partial-length-optical-corecladding 160 is non-uniform along each of partial-length opticalwaveguides 122. The partial-length-optical-core refractive index isgreater than the partial-length-optical-core first-cladding-resinrefractive index. The preceding subject matter of this paragraphcharacterizes example 18 of the present disclosure, wherein example 18also includes the subject matter according to example 16 or 17, above.

Similar to full-length optical waveguide 102, by being non-uniform alongthe length of partial-length optical waveguides 122, electromagneticradiation 118 is permitted to exit partial-length optical core 138 viapartial-length peripheral surface 144. Moreover, by firstpartial-length-optical-core cladding resin 162 having a refractive indexthat is less than that of partial-length optical core 138,electromagnetic radiation 118, upon entering partial-length optical core138, is trapped within partial-length optical core 138 other than theregions where first partial-length-optical-core cladding resin 162 isnot present. As a result, partial-length optical waveguides 122 may beconstructed to provide a desired amount of electromagnetic radiation118, exiting various positions along partial-length peripheral surface144, such as to ensure a desired amount of electromagnetic radiation118, penetrating the shadows of elongate filaments 104.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 5, 7, 10,and 11, partial-length peripheral surface 144 of partial-length opticalcore 138 of each of partial-length optical waveguides 122 haspartial-length-peripheral-surface regions 129 devoid of firstpartial-length-optical-core cladding resin 162.Partial-length-optical-core cladding 160 further comprises secondpartial-length-optical-core cladding resin 164, having apartial-length-optical-core second-cladding-resin refractive index.Second partial-length-optical-core cladding resin 164 coverspartial-length-peripheral-surface regions 129 of partial-lengthperipheral surface 144. The partial-length-optical-coresecond-cladding-resin refractive index is greater than thepartial-length-optical-core first-cladding-resin refractive index. Thepreceding subject matter of this paragraph characterizes example 19 ofthe present disclosure, wherein example 19 also includes the subjectmatter according to example 18, above.

By covering partial-length-peripheral-surface regions 129 with secondpartial-length-optical-core cladding resin 164, a desired refractiveindex thereof may be selected to optimize how electromagnetic radiation118 exits partial-length peripheral surface 144. Additionally oralternatively, with partial-length-peripheral-surface regions 129covered with second partial-length-optical-core cladding resin 164, theintegrity of first partial-length-optical-core cladding resin 162 may beensured, such that it does not peel or break off during storage ofpartial-length optical waveguides 122 and during construction offeedstock line 100.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 5, 7, and11, second partial-length-optical-core cladding resin 164 also coversfirst partial-length-optical-core cladding resin 162. The precedingsubject matter of this paragraph characterizes example 20 of the presentdisclosure, wherein example 20 also includes the subject matteraccording to example 19, above.

Partial-length optical waveguides 122 according to example 20 may bemore easily manufactured, in that partial-length optical core 138 withfirst partial-length-optical-core cladding resin 162 simply may be fullycoated with second partial-length-optical-core cladding resin 164.Additionally or alternatively, the integrity of partial-length opticalwaveguides 122 may be maintained during storage thereof and duringconstruction of feedstock line 100.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 5, 7, 10,and 11, resin 124 has a resin refractive index. The resin refractiveindex is greater than the partial-length-optical-coresecond-cladding-resin refractive index. The preceding subject matter ofthis paragraph characterizes example 21 of the present disclosure,wherein example 21 also includes the subject matter according to example19 or 20, above.

Because second partial-length-optical-core cladding resin 164 has arefractive index less than that of resin 124, electromagnetic radiation118 will be permitted to exit second partial-length-optical-corecladding resin 164 to penetrate and cure resin 124 when feedstock line100 is being used to additively manufacture object 136.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 5, 7, and12, partial-length peripheral surface 144 of partial-length optical core138 of each of partial-length optical waveguides 122 has a surfaceroughness that is selected such that when electromagnetic radiation 118enters partial-length optical core 138 via at least one of firstpartial-length-optical-core end face 140, secondpartial-length-optical-core end face 142, or partial-length peripheralsurface 144, at least a portion of electromagnetic radiation 118 exitspartial-length optical core 138 via partial-length peripheral surface144 to irradiate, in interior volume 182 of feedstock line 100, resin124 that, due at least in part to elongate filaments 104, is notdirectly accessible to electromagnetic radiation 118, incident onexterior surface 180 of feedstock line 100. The preceding subject matterof this paragraph characterizes example 22 of the present disclosure,wherein example 22 also includes the subject matter according to example16 or 17, above.

Rather than relying on refractive-index properties of a cladding toensure desired dispersal of electromagnetic radiation 118 frompartial-length optical core 138 via partial-length peripheral surface144, the surface roughness of partial-length peripheral surface 144 isselected such that electromagnetic radiation 118 exits partial-lengthoptical core 138 at desired amounts along the length of partial-lengthperipheral surface 144. For example, the surface roughness may createregions of internal reflection of electromagnetic radiation 118 withinpartial-length optical core 138 and may create regions whereelectromagnetic radiation 118 is permitted to escape partial-lengthoptical core 138.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 5, 7, and12, each of partial-length optical waveguides 122 is devoid of anycladding that covers partial-length optical core 138. The precedingsubject matter of this paragraph characterizes example 23 of the presentdisclosure, wherein example 23 also includes the subject matteraccording to example 22, above.

Partial-length optical waveguides 122 without any cladding may be lessexpensive to manufacture than partial-length optical waveguides 122 withcladding. Additionally, the difference of refractive indexes between acladding and resin 124 need not be taken into account when selectingresin 124 for feedstock line 100.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 6, 7, and15-17, optical direction modifiers 123 comprise opticaldirection-modifying particles 186. Optical direction-modifying particles186 are configured to at least one of reflect, refract, diffract, orRayleigh-scatter electromagnetic radiation 118, incident on outersurface 184 of any one of optical direction-modifying particles 186, todisperse, in interior volume 182 of feedstock line 100, electromagneticradiation 118 to irradiate resin 124 that, due at least in part toelongate filaments 104, is not directly accessible to electromagneticradiation 118, incident on exterior surface 180 of feedstock line 100.The preceding subject matter of this paragraph characterizes example 24of the present disclosure, wherein example 24 also includes the subjectmatter according to any one of examples 15 to 23, above.

Inclusion of optical direction-modifying particles 186 that at least oneof reflect, refract, diffract, or Rayleigh-scatter electromagneticradiation 118 provides for further dispersion of electromagneticradiation 118 within interior volume 182 for irradiation of resin 124therein. Moreover, because they are particles, opticaldirection-modifying particles 186 more easily are positioned amongelongate filaments 104 of a bundle, or tow, of elongate filaments 104.In addition, in some examples, they may be generally uniformly spacedthroughout resin 124 within interior volume 182 and effectively scatterelectromagnetic radiation 118 throughout interior volume 182 topenetrate among elongate filaments 104 and into the shadows cast byelongate filaments 104 when feedstock line 100 is being used toadditively manufacture object 136. In other examples, opticaldirection-modifying particles 186 may have a gradient of concentrationwithin interior volume 182.

Optical direction-modifying particles 186 may be of any suitablematerial, such that they reflect, refract, diffract, or Rayleigh-scatterelectromagnetic radiation 118. As illustrative, non-exclusive examples,optical direction-modifying particles 186 may be of alumina, silica,thermoplastic with desired reflective, refractive, diffractive, orRayleigh-scattering properties in connection with electromagneticradiation 118.

In some examples of feedstock line 100, a single type, or configuration,of optical direction-modifying particles 186 may be included. In otherexamples of feedstock line 100, more than one type, or configuration, ofoptical direction-modifying particles 186 may be included, withdifferent types being selected to accomplish different functions, andultimately to collectively scatter electromagnetic radiation 118 evenlythroughout interior volume 182, including into the shadows of elongatefilaments 104. For example, a first type of optical direction-modifyingparticles 186 may be configured to reflect electromagnetic radiation118, a second type of optical direction-modifying particles 186 may beconfigured to refract electromagnetic radiation 118, and a third type ofoptical direction-modifying particles 186 may be configured to diffractelectromagnetic radiation 118.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 6 and 7,each of elongate filaments 104 has a minimum outer dimension. Each ofoptical direction-modifying particles 186 has a maximum outer dimensionthat is less than one-eighth the minimum outer dimension of any one ofelongate filaments 104. The preceding subject matter of this paragraphcharacterizes example 25 of the present disclosure, wherein example 25also includes the subject matter according to example 24, above.

By having a maximum outer dimension that is less than one-eighth theminimum outer dimension of elongate filaments 104, opticaldirection-modifying particles 186 easily extend among elongate filaments104. Moreover, when feedstock line 100 is being constructed (e.g., bysystem 200 herein or according to method 300 herein), opticaldirection-modifying particles 186 may easily flow with resin 124 into abundle, or tow, of elongate filaments 104.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 6, 7, and15-17, each of optical direction-modifying particles 186 has a maximumouter dimension that is less than 1000 nm, 500 nm, 250 nm, or 200 nm.The preceding subject matter of this paragraph characterizes example 26of the present disclosure, wherein example 26 also includes the subjectmatter according to example 24 or 25, above.

Typical reinforcement fibers for composite materials often have adiameter in the range of 5 to 8 microns. By having a maximum outerdimension that is less than 1000 nm (1 micron), 500 nm (0.5 micron), 250nm (0.25 micron), or 200 nm (0.200 micron), optical direction-modifyingparticles 186 easily extend among typical sizes of elongate filaments104. Moreover, when feedstock line 100 is being constructed (e.g., bysystem 200 herein or according to method 300 herein), opticaldirection-modifying particles 186 may easily flow with resin 124 into abundle, or tow, of elongate filaments 104.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 6, 7, and15-17, electromagnetic radiation 118 has a wavelength. Each of opticaldirection-modifying particles 186 has a minimum outer dimension that isgreater than one-fourth the wavelength of electromagnetic radiation 118.The preceding subject matter of this paragraph characterizes example 27of the present disclosure, wherein example 27 also includes the subjectmatter according to any one of examples 24 to 26, above.

Selecting a minimum outer dimension of optical direction-modifyingparticles 186 that is greater than one-fourth the wavelength ofelectromagnetic radiation 118 ensures that optical direction-modifyingparticles 186 will have the intended effect of causing electromagneticradiation 118 to reflect, refract, or diffract upon hitting opticaldirection-modifying particles 186.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 6, 7, and15-17, each of optical direction-modifying particles 186 has a minimumouter dimension that is greater than or equal to 50 nm or that isgreater than or equal to 100 nm. The preceding subject matter of thisparagraph characterizes example 28 of the present disclosure, whereinexample 28 also includes the subject matter according to any one ofexamples 24 to 27, above.

Ultra-violet light having a wavelength of about 400 nm is often used inconnection with ultra-violet photopolymers. Accordingly, when resin 124comprises or consists of a photopolymer, optical direction-modifyingparticles 186 having a minimum outer dimension that is greater than orequal to 100 nm ensures that optical direction-modifying particles 186will have the intended effect of causing electromagnetic radiation 118to reflect, refract, or diffract upon hitting opticaldirection-modifying particles 186. However, in other examples, a minimumouter dimension as low as 50 nm may be appropriate.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 6 and 7,optical direction-modifying particles 186 comprise less than 10% byweight of resin 124, less than 5% by weight of resin 124, or less than1% by weight of resin 124 of feedstock line 100. The preceding subjectmatter of this paragraph characterizes example 29 of the presentdisclosure, wherein example 29 also includes the subject matteraccording to any one of examples 24 to 28, above.

By limiting optical direction-modifying particles 186 to the referencedthreshold percentages, resin 124 will operatively flow among elongatefilaments 104 when feedstock line 100 is being constructed (e.g., bysystem 200 herein or according to method 300 herein). In addition,desired properties of resin 124, feedstock line 100, and ultimatelyobject 136 will not be negatively impacted by the presence of opticaldirection-modifying particles 186.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 15-17,outer surfaces 184 of at least some of optical direction-modifyingparticles 186 are faceted. The preceding subject matter of thisparagraph characterizes example 30 of the present disclosure, whereinexample 30 also includes the subject matter according to any one ofexamples 24 to 29, above.

By being faceted, outer surfaces 184 effectively scatter electromagneticradiation 118.

As used herein, “faceted” means having a plurality of planar, orgenerally planar, surfaces. In some examples of opticaldirection-modifying particles 186 that are faceted, outer surface 184may have six or more, eight or more, ten or more, 100 or more, or even1000 or more generally planar surfaces. Optical direction-modifyingparticles 186 may be of a material that has a natural crystallinestructure that is faceted.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 15-17,outer surfaces 184 of at least some of optical direction-modifyingparticles 186 have a surface roughness that is selected such that whenelectromagnetic radiation 118 strikes outer surfaces 184,electromagnetic radiation 118 is scattered in interior volume 182 offeedstock line 100 to irradiate resin 124 that, due at least in part toelongate filaments 104, is not directly accessible to electromagneticradiation 118, incident on exterior surface 180 of feedstock line 100.The preceding subject matter of this paragraph characterizes example 31of the present disclosure, wherein example 31 also includes the subjectmatter according to any one of examples 24 to 30, above.

Having a surface roughness selected to scatter electromagnetic radiation118 facilitates the operative irradiation of resin 124 throughoutinterior volume 182, including into the shadows of elongate filaments104.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 6 and 7,resin 124 has a resin refractive index. At least some of opticaldirection-modifying particles 186 have a particle refractive index. Theparticle refractive index is greater than or less than the resinrefractive index. The preceding subject matter of this paragraphcharacterizes example 32 of the present disclosure, wherein example 32also includes the subject matter according to any one of examples 24 to31, above.

When optical direction-modifying particles 186 have a refractive indexthat is different from (e.g., that is at least 0.001 greater or lessthan) the refractive index of resin 124, electromagnetic radiation 118incident upon the outer surfaces thereof will necessarily leave theouter surfaces at a different angle, and thus will scatter throughoutresin 124, including into the shadows of elongate filaments 104.

Referring generally to FIG. 1 and particularly to, e.g., FIG. 15, atleast some of optical direction-modifying particles 186 are spherical.The preceding subject matter of this paragraph characterizes example 33of the present disclosure, wherein example 33 also includes the subjectmatter according to any one of examples 24 to 32, above.

By being spherical, optical direction-modifying particles 186 may easilybe positioned among elongate filaments 104, and when feedstock line 100is being constructed (e.g., by system 200 herein or according to method300 herein), may easily flow with resin 124 into a bundle, or tow, ofelongate filaments 104.

As used herein, “spherical” includes generally spherical and means thatsuch optical direction-modifying particles 186 have a generally uniformaspect ratio, but are not necessarily perfectly spherical. For example,optical direction-modifying particles 186 that are spherical may befaceted, as discussed herein.

Referring generally to FIG. 1 and particularly to, e.g., FIG. 16, atleast some of optical direction-modifying particles 186 are prismatic.The preceding subject matter of this paragraph characterizes example 34of the present disclosure, wherein example 34 also includes the subjectmatter according to any one of examples 24 to 33, above.

By being prismatic, optical direction-modifying particles 186 may beselected to operatively at least one of reflect, refract, or diffractelectromagnetic radiation 118, as discussed herein.

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 13 and14, system 200 for creating feedstock line 100 for additivemanufacturing of object 136 is disclosed. Feedstock line 100 has afeedstock-line length. System 200 comprises prepreg-tow supply 202,prepreg-tow separator 210, full-length-optical-waveguide supply 204,combiner 212, and at least one heater 220. Prepreg-tow supply 202 isconfigured to dispense precursor prepreg tow 208 that comprises elongatefilaments 104 and resin 124, covering elongate filaments 104.Prepreg-tow separator 210 is configured to separate precursor prepregtow 208, dispensed from prepreg-tow supply 202, into individual ones ofelongate filaments 104, at least partially covered with resin 124, orinto subsets 214 of elongate filaments 104, at least partially coveredwith resin 124. Each of subsets 214 comprises a plurality of elongatefilaments 104. Full-length-optical-waveguide supply 204 is configured todispense at least one full-length optical waveguide 102. Combiner 212 isconfigured to combine the individual ones of elongate filaments 104,originating from prepreg-tow separator 210, and at least one full-lengthoptical waveguide 102, dispensed by full-length-optical-waveguide supply204, or subsets 214 of elongate filaments 104, originating fromprepreg-tow separator 210, and at least one full-length opticalwaveguide 102, dispensed by full-length-optical-waveguide supply 204,into derivative prepreg tow 209 so that each of elongate filaments 104and at least one full-length optical waveguide 102 extend along all ofthe feedstock-line length and at least one full-length optical waveguide102 is interspersed among elongate filaments 104. At least one heater220 is configured to heat at least one of (i) resin 124 in precursorprepreg tow 208, dispensed from prepreg-tow supply 202, to a firstthreshold temperature to facilitate separation of precursor prepreg tow208 by prepreg-tow separator 210 into the individual ones of elongatefilaments 104 or into subsets 214 of elongate filaments 104; (ii) resin124 that at least partially covers the individual ones of elongatefilaments 104 or subsets 214 of elongate filaments 104, originating fromprepreg-tow separator 210, to a second threshold temperature to causewet-out of at least one full-length optical waveguide 102 and theindividual ones of elongate filaments 104 or of at least one full-lengthoptical waveguide 102 and subsets 214 of elongate filaments 104 inderivative prepreg tow 209 by resin 124; or (iii) resin 124 that atleast partially covers elongate filaments 104 in derivative prepreg tow209, originating from combiner 212, to a third threshold temperature tocause wet-out of at least one full-length optical waveguide 102 andelongate filaments 104 in derivative prepreg tow 209 by resin 124. Thepreceding subject matter of this paragraph characterizes example 35 ofthe present disclosure.

Creating feedstock line 100 from precursor prepreg tow 208 permits theuse of off-the-shelf prepreg reinforcement fiber tows. Prepreg-towseparator 210 separates precursor prepreg tow 208 into individual onesof elongate filaments 104 that are at least partially covered with resin124 or into subsets 214 of elongate filaments 104 that are at leastpartially covered with resin 124, so that at least one full-lengthoptical waveguide 102 may be operatively interspersed with elongatefilaments 104. Combiner 212 then combines elongate filaments 104 and atleast one full-length optical waveguide 102, together with resin 124,into derivative prepreg tow 209 to ultimately become feedstock line 100.At least one heater 220 heats resin 124 to facilitate one or both ofseparation of precursor prepreg tow 208 or wetting-out of elongatefilaments 104 and at least one full-length optical waveguide 102 inderivative prepreg tow 209.

Precursor prepreg tow 208 may take any suitable form depending on thedesired properties of feedstock line 100. As mentioned, precursorprepreg tow 208 may be (but is not required to be) an off-the-shelfprecursor prepreg tow, with such examples including tows having 1000,3000, 6000, 12000, 24000, or 48000 continuous individual fibers withinthe tow, but other examples also may be used.

Prepreg-tow separator 210 may take any suitable configuration, such thatit is configured to operatively separate precursor prepreg tow 208 intoindividual ones of elongate filaments 104 or subsets 214 thereof. Forexample, prepreg-tow separator 210 may comprise at least one of a knife,an air knife, a comb, a mesh, a screen, a series of polished idlers, andother mechanisms known in the art.

Combiner 212 may take any suitable configuration, such that it isconfigured to operatively combine elongate filaments 104 with at leastone full-length optical waveguide 102, such that at least onefull-length optical waveguide 102 becomes interspersed among elongatefilaments 104, and such that elongate filaments 104 and at least onefull-length optical waveguide 102 are at least partially covered byresin 124. For example, combiner 212 may at least one of twist, weave,braid, or otherwise bundle elongate filaments 104 together with at leastone full-length optical waveguide 102. Combiner 212 also may include afixator, such as a mesh or screen, through which elongate filaments 104and full-length optical waveguide(s) extend, and which prevents thetwisting, weaving, braiding, or bundling from propagating upstream ofcombiner 212.

Heater 220 may take any suitable configuration, such that it isconfigured to heat resin 124 at an operative location as feedstock line100 is being created. In some examples, heater 220 may utilize a heatedfluid stream, such as a heated gas stream to heat resin 124.Additionally or alternatively, in some examples, heater 220 may comprisea resistive, or other type of, heater to heat resin 124, such as itpasses through prepreg-tow separator 210 or combiner 212, such as withprepreg-tow separator 210 comprising heater 220 or combiner 212comprising heater 220, respectively.

In some examples, two or more of the first threshold temperature, thesecond threshold temperature, or the third threshold temperature may bethe same temperature. In other examples, two or more of the firstthreshold temperature, the second threshold temperature, or the thirdthreshold temperature may be different temperatures.

Referring generally to FIG. 2, elongate filaments 104 are opaque toelectromagnetic radiation 118. The preceding subject matter of thisparagraph characterizes example 36 of the present disclosure, whereinexample 36 also includes the subject matter according to example 35,above.

As discussed, elongate filaments 104 that are opaque to electromagneticradiation 118 may be well suited for inclusion in feedstock line 100, asat least one full-length optical waveguide 102 operatively will receiveelectromagnetic radiation 118 and disperse it into the shadows ofelongate filaments 104 when feedstock line 100 is being used toadditively manufacture object 136 with in situ curing thereof.

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 9-12, atleast one full-length optical waveguide 102 comprises full-lengthoptical core 110. Full-length optical core 110 comprises firstfull-length-optical-core end face 112, second full-length-optical-coreend face 114, opposite first full-length-optical-core end face 112, andfull-length peripheral surface 116, extending between firstfull-length-optical-core end face 112 and secondfull-length-optical-core end face 114. At least one full-length opticalwaveguide 102 is configured such that when electromagnetic radiation 118enters full-length optical core 110 via at least one of firstfull-length-optical-core end face 112, second full-length-optical-coreend face 114, or full-length peripheral surface 116, at least a portionof electromagnetic radiation 118 exits full-length optical core 110 viafull-length peripheral surface 116. The preceding subject matter of thisparagraph characterizes example 37 of the present disclosure, whereinexample 37 also includes the subject matter according to example 35 or36, above.

Accordingly, when feedstock line 100 is used to additively manufactureobject 136 with in situ curing thereof (i.e., with electromagneticradiation 118 entering full-length optical core 110), at least a portionof electromagnetic radiation 118 will be emitted from full-lengthoptical core 110 at a position that is spaced-apart from where itentered full-length optical core 110. As a result, electromagneticradiation may be dispersed throughout interior volume 182 of feedstockline 100 for operative irradiation of resin 124.

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 9-12, atleast one full-length optical waveguide 102 is configured such that whenelectromagnetic radiation 118 enters first full-length-optical-core endface 112 of full-length optical core 110, an initial portion ofelectromagnetic radiation 118 exits full-length optical core 110 viafull-length peripheral surface 116 and a final portion ofelectromagnetic radiation 118, remaining in full-length optical core 110after the initial portion of electromagnetic radiation 118 exitsfull-length optical core 110, exits full-length optical core 110 viasecond full-length-optical-core end face 114. The preceding subjectmatter of this paragraph characterizes example 38 of the presentdisclosure, wherein example 38 also includes the subject matteraccording to example 37, above.

In other words, in some examples of feedstock line 100, ifelectromagnetic radiation 118 enters first full-length-optical-core endface 112, it will exit both full-length peripheral surface 116 andsecond full-length-optical-core end face 114, as opposed, for example,to electromagnetic radiation 118 being fully emitted via full-lengthperipheral surface 116. As discussed, such examples of feedstock line100 are well suited for additive manufacturing systems and methods inwhich electromagnetic radiation 118 is directed at firstfull-length-optical-core end face 112 as feedstock line 100 is beingconstructed and as object 136 is being manufactured.

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 9-12, atleast one full-length optical waveguide 102 is configured such that theinitial portion of electromagnetic radiation 118, which exitsfull-length optical core 110 via full-length peripheral surface 116, isgreater than or equal to the final portion of electromagnetic radiation118, which exits full-length optical core 110 via secondfull-length-optical-core end face 114. The preceding subject matter ofthis paragraph characterizes example 39 of the present disclosure,wherein example 39 also includes the subject matter according to example38, above.

As discussed, in such configurations, it is ensured that a desiredamount of electromagnetic radiation 118 exits full-length optical core110 via full-length peripheral surface 116 to operatively cure resin 124among elongate filaments 104 within interior volume 182 of feedstockline 100 when feedstock line 100 is used to additively manufactureobject 136.

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 9-11,full-length optical core 110 has a full-length-optical-core refractiveindex. At least one full-length optical waveguide 102 further comprisesfull-length-optical-core cladding 154, at least partially coveringfull-length optical core 110. Full-length-optical-core cladding 154comprises at least first full-length-optical-core cladding resin 156,having a full-length-optical-core first-cladding-resin refractive index.Full-length-optical-core cladding 154 is non-uniform along at least onefull-length optical waveguide 102. The full-length-optical-corerefractive index is greater than the full-length-optical-corefirst-cladding-resin refractive index. The preceding subject matter ofthis paragraph characterizes example 40 of the present disclosure,wherein example 40 also includes the subject matter according to any oneof examples 37 to 39, above.

As discussed, by full-length-optical-core cladding 154 being non-uniformalong the length of the full-length optical waveguide, electromagneticradiation 118 is permitted to exit full-length optical core 110 viafull-length peripheral surface 116. Moreover, by firstfull-length-optical-core cladding resin 156 having a refractive indexthat is less than that of full-length optical core 110, electromagneticradiation 118, upon entering full-length optical core 110, is trappedwithin full-length optical core 110 other than the regions where firstfull-length-optical-core cladding resin 156 is not present. As a result,full-length optical waveguide 102 may be constructed to provide adesired amount of electromagnetic radiation 118, exiting variouspositions along full-length peripheral surface 116, such as to ensure adesired amount of electromagnetic radiation 118, penetrating the shadowsof elongate filaments 104 when feedstock line 100 is used to additivelymanufacture object 136.

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 10 and11, full-length peripheral surface 116 hasfull-length-peripheral-surface regions 127 devoid of firstfull-length-optical-core cladding resin 156. Full-length-optical-corecladding 154 further comprises second full-length-optical-core claddingresin 158, having a full-length-optical-core second-cladding-resinrefractive index. Second full-length-optical-core cladding resin 158covers full-length-peripheral-surface regions 127 of full-lengthperipheral surface 116. The full-length-optical-coresecond-cladding-resin refractive index is greater than thefull-length-optical-core first-cladding-resin refractive index. Thepreceding subject matter of this paragraph characterizes example 41 ofthe present disclosure, wherein example 41 also includes the subjectmatter according to example 40, above.

As discussed, by covering full-length-peripheral-surface regions 127with second full-length-optical-core cladding resin 158, a desiredrefractive index thereof may be selected to optimize how electromagneticradiation 118 exits full-length peripheral surface 116. Additionally oralternatively, with full-length-peripheral-surface regions 127 coveredwith second full-length-optical-core cladding resin 158, the integrityof first full-length-optical-core cladding resin 156 may be ensured,such that it does not peel or break off during storage of at least onefull-length optical waveguide 102 and during construction of feedstockline 100.

Referring generally to FIG. 2 and particularly to, e.g., FIG. 11, secondfull-length-optical-core cladding resin 158 also covers firstfull-length-optical-core cladding resin 156. The preceding subjectmatter of this paragraph characterizes example 42 of the presentdisclosure, wherein example 42 also includes the subject matteraccording to example 41, above.

As discussed, full-length optical waveguides, such as according toexample 42, may be more easily manufactured, in that full-length opticalcore 110 with first full-length-optical-core cladding resin 156 simplymay be fully coated with second full-length-optical-core cladding resin158. Additionally or alternatively, the integrity of full-length opticalwaveguides may be maintained during storage thereof and duringconstruction of feedstock line 100.

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 10 and11, resin 124 has a resin refractive index. The resin refractive indexis greater than the full-length-optical-core second-cladding-resinrefractive index. The preceding subject matter of this paragraphcharacterizes example 43 of the present disclosure, wherein example 43also includes the subject matter according to example 41 or 42, above.

As discussed, because second full-length-optical-core cladding resin 158has a refractive index less than that of resin 124, electromagneticradiation 118 will be permitted to exit second full-length-optical-corecladding resin 158 to penetrate and cure resin 124 when feedstock line100 is used to additively manufacture object 136.

Referring generally to FIG. 2 and particularly to, e.g., FIG. 12,full-length peripheral surface 116 has a surface roughness that isselected such that when electromagnetic radiation 118 enters full-lengthoptical core 110 via at least one of first full-length-optical-core endface 112, second full-length-optical-core end face 114, or full-lengthperipheral surface 116, at least a portion of electromagnetic radiation118 exits full-length optical core 110 via full-length peripheralsurface 116. The preceding subject matter of this paragraphcharacterizes example 44 of the present disclosure, wherein example 44also includes the subject matter according to any one of examples 37 to39, above.

As discussed, rather than relying on refractive-index properties of acladding to ensure desired dispersal of electromagnetic radiation 118from full-length optical core 110 via full-length peripheral surface116, the surface roughness of full-length peripheral surface 116 isselected such that electromagnetic radiation 118 exits full-lengthoptical core 110 at desired amounts along the length of full-lengthperipheral surface 116. For example, the surface roughness may createregions of internal reflection of electromagnetic radiation 118 withinfull-length optical core 110 and may create regions whereelectromagnetic radiation 118 is permitted to escape full-length opticalcore 110.

Referring generally to FIG. 2 and particularly to, e.g., FIG. 12, atleast one full-length optical waveguide 102 is devoid of any claddingthat covers full-length optical core 110. The preceding subject matterof this paragraph characterizes example 45 of the present disclosure,wherein example 45 also includes the subject matter according to example44, above.

As discussed, full-length optical waveguides without any cladding may beless expensive to manufacture than full-length optical waveguides withcladding. Additionally, the difference of refractive indexes between acladding and resin 124 need not be taken into account when selectingresin 124 for feedstock line 100.

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 13 and14, system 200 further comprises resin supply 206. Resin supply 206 isconfigured to provide additional resin 125 to be applied to at least oneof (i) precursor prepreg tow 208, dispensed from prepreg-tow supply 202,(ii) the individual ones of elongate filaments 104, at least partiallycovered with resin 124, or subsets 214 of elongate filaments 104, atleast partially covered with resin 124, originating from prepreg-towseparator 210, (iii) at least one full-length optical waveguide 102,dispensed from full-length-optical-waveguide supply 204, or (iv)derivative prepreg tow 209, originating from combiner 212, such thatelongate filaments 104 and at least one full-length optical waveguide102 in derivative prepreg tow 209 are covered with resin 124 andadditional resin 125. The preceding subject matter of this paragraphcharacterizes example 46 of the present disclosure, wherein example 46also includes the subject matter according to any one of examples 35 to45, above.

By applying additional resin 125 to elongate filaments 104 andfull-length optical waveguide(s), full wet-out of elongate filaments 104and full-length optical waveguide(s) may be achieved in feedstock line100.

Resin supply 206 may take any suitable configuration, such that it isconfigured to operatively dispense and apply additional resin 125 at anoperative location. For example, resin supply 206 may be configured tospray or mist additional resin 125. Additionally or alternatively, resinsupply 206 may include a reservoir or bath of additional resin 125,through which is pulled at least one of precursor prepreg tow 208,individual ones of elongate filaments 104, subsets 214 of elongatefilaments 104, full-length optical waveguide(s), or derivative prepregtow 209.

In some examples, additional resin 125 may be the same as resin 124. Inother examples, additional resin 125 may be different from resin 124.

In some examples, system 200 may further comprise chamber 224 betweenprepreg-tow separator 210 and combiner 212, and through which individualones of elongate filaments 104 or subsets 214 of elongate filaments 104pass as feedstock line 100 is being created. In some such examples, atleast one full-length optical waveguide 102 also extends through chamber224. Moreover, in some such examples, additional resin 125 is applied toat least elongate filaments 104, and in some examples, also to at leastone full-length optical waveguide 102, in chamber 224.

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 13 and14, prepreg-tow separator 210 is configured to impart a first electricalcharge to elongate filaments 104 or to resin 124 as precursor prepregtow 208 is separated into the individual ones of elongate filaments 104,at least partially covered with resin 124, or into subsets 214 ofelongate filaments 104, at least partially covered with resin 124.Additionally, resin supply 206 is configured to impart a secondelectrical charge to additional resin 125 when additional resin 125 isapplied to at least one of (i) the individual ones of elongate filaments104, at least partially covered by resin 124, or subsets 214 of elongatefilaments 104, at least partially covered by resin 124 and originatingfrom prepreg-tow separator 210, or (ii) derivative prepreg tow 209,originating from combiner 212, such that elongate filaments 104 and atleast one full-length optical waveguide 102 in derivative prepreg tow209 are covered with resin 124 and additional resin 125. Also, thesecond electrical charge and the first electrical charge have oppositesigns. The preceding subject matter of this paragraph characterizesexample 47 of the present disclosure, wherein example 47 also includesthe subject matter according to example 46, above.

By imparting a first electrical charge to elongate filaments 104 orresin 124 and by imparting a second opposite charge to additional resin125 as it is applied to elongate filaments 104 and resin 124, additionalresin 125 will be electrostatically attracted to elongate filaments 104.

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 13 and14, combiner 212 is configured to at least one of twist, weave, or braidthe individual ones of elongate filaments 104 and at least onefull-length optical waveguide 102, dispensed byfull-length-optical-waveguide supply 204, or subsets 214 of elongatefilaments 104, originating from prepreg-tow separator 210, and at leastone full-length optical waveguide 102, dispensed byfull-length-optical-waveguide supply 204, into derivative prepreg tow209. The preceding subject matter of this paragraph characterizesexample 48 of the present disclosure, wherein example 48 also includesthe subject matter according to any one of examples 35 to 47, above.

As discussed, by being twisted with, woven with, or braided withelongate filaments 104, at least one full-length optical waveguide 102is interspersed with elongate filaments 104 so that electromagneticradiation 118, exiting at least one full-length optical waveguide 102,is delivered to regions of interior volume 182 that are in the shadowsof elongate filaments 104 when feedstock line 100 is used to additivelymanufacture object 136.

As an example, combiner 212 may comprise a spool that winds upderivative prepreg tow 209 while simultaneously twisting derivativeprepreg tow 209. Other mechanisms for twisting, weaving, or braidingmulti-filament structures, as known in the art, also may be used.

Referring generally to FIG. 2 and particularly to, e.g., FIG. 14, system200 further comprises optical-direction-modifier supply 216, configuredto dispense optical direction modifiers 123 to be applied to theindividual ones of elongate filaments 104, at least partially coveredwith resin 124, or subsets 214 of elongate filaments 104, at leastpartially covered with resin 124, originating from prepreg-tow separator210. Combiner 212 is further configured to combine optical directionmodifiers 123 with at least one full-length optical waveguide 102,dispensed by full-length-optical-waveguide supply 204, and theindividual ones of elongate filaments 104, at least partially covered byresin 124, or subsets 214 of elongate filaments 104, at least partiallycovered by resin 124, originating from prepreg-tow separator 210, intoderivative prepreg tow 209 so that optical direction modifiers 123 areinterspersed among elongate filaments 104 and at least partially coveredby resin 124. Each of optical direction modifiers 123 has outer surface184. Each of optical direction modifiers 123 is configured such thatwhen electromagnetic radiation 118 strikes outer surface 184 from afirst direction, at least a portion of electromagnetic radiation 118departs outer surface 184 in a second direction that is at an angle tothe first direction. The preceding subject matter of this paragraphcharacterizes example 49 of the present disclosure, wherein example 49also includes the subject matter according to any one of examples 35 to48, above.

By applying optical direction modifiers 123 to elongate filaments 104and resin 124 to become part of feedstock line 100 being created bysystem 200, additional dispersion of electromagnetic radiation 118within interior volume 182 for irradiation of resin 124 therein may beachieved when feedstock line 100 is used to additively manufactureobject 136. Moreover, as discussed, by being shorter than full-lengthoptical waveguides, optical direction modifiers 123 may more easilyextend among elongate filaments 104 within derivative prepreg tow 209.Not only may optical direction modifiers 123 serve to disperse, orscatter, electromagnetic radiation 118 into the shadows of elongatefilaments 104, but they also may serve to redirect electromagneticradiation 118 to at least one full-length optical waveguide 102 forpenetration into the shadows of elongate filaments 104 by at least onefull-length optical waveguide 102.

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 9-12,optical direction modifiers 123 comprise partial-length opticalwaveguides 122. Each of partial-length optical waveguides 122 comprisespartial-length optical core 138. Partial-length optical core 138 of eachof partial-length optical waveguides 122 comprises firstpartial-length-optical-core end face 140, secondpartial-length-optical-core end face 142, opposite firstpartial-length-optical-core end face 140, and partial-length peripheralsurface 144, extending between first partial-length-optical-core endface 140 and second partial-length-optical-core end face 142. Each ofpartial-length optical waveguides 122 is configured such that whenelectromagnetic radiation 118 enters partial-length optical core 138 viaat least one of first partial-length-optical-core end face 140, secondpartial-length-optical-core end face 142, or partial-length peripheralsurface 144, at least a portion of electromagnetic radiation 118 exitspartial-length optical core 138 via partial-length peripheral surface144. The preceding subject matter of this paragraph characterizesexample 50 of the present disclosure, wherein example 50 also includesthe subject matter according to example 49, above.

As discussed, in some examples, optical direction modifiers 123 aresimilar in construction to full-length optical waveguides but areshorter in length.

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 9-11,partial-length optical core 138 has a partial-length-optical-corerefractive index. Each of partial-length optical waveguides 122 furthercomprises partial-length-optical-core cladding 160, at least partiallycovering partial-length optical core 138. Partial-length-optical-corecladding 160 comprises at least first partial-length-optical-corecladding resin 162, having a partial-length-optical-corefirst-cladding-resin refractive index. Partial-length-optical-corecladding 160 is non-uniform along each of partial-length opticalwaveguides 122. The partial-length-optical-core refractive index isgreater than the partial-length-optical-core first-cladding-resinrefractive index. The preceding subject matter of this paragraphcharacterizes example 51 of the present disclosure, wherein example 51also includes the subject matter according to example 50, above.

As discussed, similar to full-length optical waveguide 102, bypartial-length-optical-core cladding 160 being non-uniform along thelength of partial-length optical waveguides 122, electromagneticradiation 118 is permitted to exit partial-length optical core 138 viapartial-length peripheral surface 144. Moreover, by firstpartial-length-optical-core cladding resin 162 having a refractive indexthat is less than that of partial-length optical core 138,electromagnetic radiation 118, upon entering partial-length optical core138, is trapped within partial-length optical core 138 other than theregions where first partial-length-optical-core cladding resin 162 isnot present. As a result, partial-length optical waveguides 122 may beconstructed to provide a desired amount of electromagnetic radiation118, exiting various positions along partial-length peripheral surface144, such as to ensure a desired amount of electromagnetic radiation118, penetrating the shadows of elongate filaments 104 when feedstockline 100 is being used to additively manufacture object 136.

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 10 and11, partial-length peripheral surface 144 of partial-length optical core138 of each of partial-length optical waveguides 122 haspartial-length-peripheral-surface regions 129 devoid of firstpartial-length-optical-core cladding resin 162.Partial-length-optical-core cladding 160 further comprises secondpartial-length-optical-core cladding resin 164, having apartial-length-optical-core second-cladding-resin refractive index.Second partial-length-optical-core cladding resin 164 coverspartial-length-peripheral-surface regions 129 of partial-lengthperipheral surface 144. The partial-length-optical-coresecond-cladding-resin refractive index is greater than thepartial-length-optical-core first-cladding-resin refractive index. Thepreceding subject matter of this paragraph characterizes example 52 ofthe present disclosure, wherein example 52 also includes the subjectmatter according to example 51, above.

As discussed, by covering partial-length-peripheral-surface regions 129with second partial-length-optical-core cladding resin 164, a desiredrefractive index thereof may be selected to optimize how electromagneticradiation 118 exits partial-length peripheral surface 144. Additionallyor alternatively, with partial-length-peripheral-surface regions 129covered with second partial-length-optical-core cladding resin 164, theintegrity of first partial-length-optical-core cladding resin 162 may beensured, such that it does not peel or break off during storage ofpartial-length optical waveguides 122 and during construction offeedstock line 100.

Referring generally to FIG. 2 and particularly to, e.g., FIG. 11, secondpartial-length-optical-core cladding resin 164 also covers firstpartial-length-optical-core cladding resin 162. The preceding subjectmatter of this paragraph characterizes example 53 of the presentdisclosure, wherein example 53 also includes the subject matteraccording to example 52, above.

As discussed, partial-length optical waveguides 122, such as accordingto example 53, may be more easily manufactured, in that partial-lengthoptical core 138 with first partial-length-optical-core cladding resin162 simply may be fully coated with second partial-length-optical-corecladding resin 164. Additionally or alternatively, the integrity ofpartial-length optical waveguides 122 may be maintained during storagethereof and during construction of feedstock line 100.

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 10 and11, resin 124 has a resin refractive index. The resin refractive indexis greater than the partial-length-optical-core second-cladding-resinrefractive index. The preceding subject matter of this paragraphcharacterizes example 54 of the present disclosure, wherein example 54also includes the subject matter according to example 52 or 53, above.

Again, because second partial-length-optical-core cladding resin 164 hasa refractive index less than that of resin 124, electromagneticradiation 118 will be permitted to exit secondpartial-length-optical-core cladding resin 164 to penetrate and cureresin 124 when feedstock line 100 is being used to additivelymanufacture object 136.

Referring generally to FIG. 2 and particularly to, e.g., FIG. 12,partial-length peripheral surface 144 of partial-length optical core 138of each of partial-length optical waveguides 122 has a surface roughnessthat is selected such that when electromagnetic radiation 118 enterspartial-length optical core 138 via at least one of firstpartial-length-optical-core end face 140, secondpartial-length-optical-core end face 142, or partial-length peripheralsurface 144, at least a portion of electromagnetic radiation 118 exitspartial-length optical core 138 via partial-length peripheral surface144. The preceding subject matter of this paragraph characterizesexample 55 of the present disclosure, wherein example 55 also includesthe subject matter according to example 50 or 51, above.

Again, rather than relying on refractive-index properties of a claddingto ensure desired dispersal of electromagnetic radiation 118 frompartial-length optical core 138 via partial-length peripheral surface144, the surface roughness of partial-length peripheral surface 144 isselected such that electromagnetic radiation 118 exits partial-lengthoptical core 138 at desired amounts along the length of partial-lengthperipheral surface 144. For example, the surface roughness may createregions of internal reflection of electromagnetic radiation 118 withinpartial-length optical core 138 and may create regions whereelectromagnetic radiation 118 is permitted to escape partial-lengthoptical core 138.

Referring generally to FIG. 2 and particularly to, e.g., FIG. 12, eachof partial-length optical waveguides 122 is devoid of any cladding thatcovers partial-length optical core 138. The preceding subject matter ofthis paragraph characterizes example 56 of the present disclosure,wherein example 56 also includes the subject matter according to example55, above.

Again, partial-length optical waveguides 122 without any cladding may beless expensive to manufacture than partial-length optical waveguides 122with cladding. Additionally, the difference of refractive indexesbetween a cladding and resin 124 need not be taken into account whenselecting resin 124 for feedstock line 100.

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 15-17,optical direction modifiers 123 comprise optical direction-modifyingparticles 186. Optical direction-modifying particles 186 are configuredto at least one of reflect, refract, diffract, or Rayleigh-scatterelectromagnetic radiation 118, incident on outer surface 184 of any oneof optical direction-modifying particles 186 to disperse electromagneticradiation 118. The preceding subject matter of this paragraphcharacterizes example 57 of the present disclosure, wherein example 57also includes the subject matter according to any one of examples 49 to56, above.

As discussed, inclusion of optical direction-modifying particles 186that at least one of reflect, refract, diffract, or Rayleigh-scatterelectromagnetic radiation 118 provides for further dispersion ofelectromagnetic radiation 118 within interior volume 182 for irradiationof resin 124 therein when feedstock line 100 is being used to additivelymanufacture object 136. Moreover, because they are particles, opticaldirection-modifying particles 186 more easily are interspersed amongelongate filaments 104 when applied thereto. In addition, in someexamples of feedstock line 100, they may be generally uniformly spacedthroughout resin 124 within interior volume 182 and effectively scatterelectromagnetic radiation 118 throughout interior volume 182 topenetrate among elongate filaments 104 and into the shadows cast byelongate filaments 104 when feedstock line 100 is being used toadditively manufacture object 136. In other examples of feedstock line100, optical direction-modifying particles 186 may have a gradient ofconcentration within interior volume 182

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 6, 7, and15-17, each of elongate filaments 104 has a minimum outer dimension.Each of optical direction-modifying particles 186 has a maximum outerdimension that is less than one-eighth the minimum outer dimension ofany one of elongate filaments 104. The preceding subject matter of thisparagraph characterizes example 58 of the present disclosure, whereinexample 58 also includes the subject matter according to example 57,above.

Again, by having a maximum outer dimension that is less than one-eighththe minimum outer dimension of elongate filaments 104, opticaldirection-modifying particles 186 are easily dispersed between elongatefilaments 104. Moreover, optical direction-modifying particles 186 mayeasily flow with resin 124 to operatively disperse opticaldirection-modifying particles 186 throughout feedstock line 100,including into the shadows of elongate filaments 104.

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 15-17,each of optical direction-modifying particles 186 has a maximum outerdimension that is less than 1000 nm, 500 nm, 250 nm, or 200 nm. Thepreceding subject matter of this paragraph characterizes example 59 ofthe present disclosure, wherein example 59 also includes the subjectmatter according to example 57 or 58, above.

As discussed, typical reinforcement fibers for composite materials oftenhave a diameter in the range of 5 to 8 microns. By having a maximumouter dimension that is less than 1000 nm (1 micron), 500 nm (0.5micron), 250 nm (0.25 micron), or 200 nm (0.200 micron), opticaldirection-modifying particles 186 easily extend among typical sizes ofelongate filaments 104. Moreover, optical direction-modifying particles186 may easily flow with resin 124 to operatively disperse opticaldirection-modifying particles 186 throughout feedstock line 100,including into the shadows of elongate filaments 104.

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 15-17,electromagnetic radiation 118 has a wavelength. Each of opticaldirection-modifying particles 186 has a minimum outer dimension that isgreater than one-fourth the wavelength of electromagnetic radiation 118.The preceding subject matter of this paragraph characterizes example 60of the present disclosure, wherein example 50 also includes the subjectmatter according to any one of examples 57 to 59, above.

Again, selecting a minimum outer dimension of opticaldirection-modifying particles 186 that is greater than one-fourth thewavelength of electromagnetic radiation 118 that will be used whenadditively manufacturing object 136 ensures that opticaldirection-modifying particles 186 will have the intended effect ofcausing electromagnetic radiation 118 to reflect, refract, or diffractupon hitting optical direction-modifying particles 186.

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 15-17,each of optical direction-modifying particles 186 has a minimum outerdimension that is greater than or equal to 50 nm or that is greater thanor equal to 100 nm. The preceding subject matter of this paragraphcharacterizes example 61 of the present disclosure, wherein example 61also includes the subject matter according to any one of examples 57 to60, above.

As discussed, ultra-violet light having a wavelength of about 400 nm isoften used in connection with ultra-violet photopolymers. Accordingly,when resin 124 comprises or consists of a photopolymer, opticaldirection-modifying particles 186 having a minimum outer dimension thatis greater than or equal to 100 nm ensures that opticaldirection-modifying particles 186 will have the intended effect ofcausing electromagnetic radiation 118 to reflect, refract, or diffractupon hitting optical direction-modifying particles 186. However, inother examples, a minimum outer dimension as low as 50 nm may beappropriate.

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 1, 6, and7, in feedstock line 100, optical direction-modifying particles 186comprise less than 10% by weight of resin 124, less than 5% by weight ofresin 124, or less than 1% by weight of resin 124. The preceding subjectmatter of this paragraph characterizes example 62 of the presentdisclosure, wherein example 62 also includes the subject matteraccording to any one of examples 57 to 61, above.

As discussed, by limiting optical direction-modifying particles 186 tothe referenced threshold percentages, resin 124 will operatively flowamong elongate filaments 104 when combiner 212 combines elongatefilaments 104, at least one full-length optical waveguide 102, andoptical direction-modifying particles 186. In addition, desiredproperties of resin 124, feedstock line 100, and ultimately object 136will not be negatively impacted by the presence of opticaldirection-modifying particles 186.

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 15-17,outer surfaces 184 of at least some of optical direction-modifyingparticles 186 are faceted. The preceding subject matter of thisparagraph characterizes example 63 of the present disclosure, whereinexample 63 also includes the subject matter according to any one ofexamples 57 to 62, above.

Again, by being faceted, outer surfaces 184 effectively scatterelectromagnetic radiation 118.

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 15-17,outer surfaces 184 of at least some of optical direction-modifyingparticles 186 have a surface roughness that is selected such that whenelectromagnetic radiation 118 strikes outer surfaces 184,electromagnetic radiation 118 is scattered. The preceding subject matterof this paragraph characterizes example 64 of the present disclosure,wherein example 64 also includes the subject matter according to any oneof examples 57 to 63, above.

As discussed, having a surface roughness selected to scatterelectromagnetic radiation 118 facilitates the operative irradiation ofresin 124 throughout feedstock line 100, including into the shadows ofelongate filaments 104, when feedstock line 100 is being used toadditively manufacture object 136.

Referring generally to FIG. 2 and particularly to, e.g., FIGS. 6 and 7,resin 124 has a resin refractive index. At least some of opticaldirection-modifying particles 186 have a particle refractive index. Theparticle refractive index is greater than or less than the resinrefractive index. The preceding subject matter of this paragraphcharacterizes example 65 of the present disclosure, wherein example 65also includes the subject matter according to any one of examples 57 to64, above.

Again, when optical direction-modifying particles 186 have a refractiveindex that is different from the refractive index of resin 124,electromagnetic radiation 118 incident upon the outer surfaces thereofwill necessarily leave the outer surfaces at a different angle, and thuswill scatter throughout resin 124, including into the shadows ofelongate filaments 104.

Referring generally to FIG. 2 and particularly to, e.g., FIG. 15, atleast some of optical direction-modifying particles 186 are spherical.The preceding subject matter of this paragraph characterizes example 66of the present disclosure, wherein example 66 also includes the subjectmatter according to any one of examples 57 to 65, above.

Again, by being spherical, optical direction-modifying particles 186easily may be positioned among elongate filaments 104 and may easilyflow with resin 124 as combiner 212 combines elongate filaments 104 andoptical direction-modifying particles 186.

Referring generally to FIG. 2 and particularly to, e.g., FIG. 16, atleast some of optical direction-modifying particles 186 are prismatic.The preceding subject matter of this paragraph characterizes example 67of the present disclosure, wherein example 67 also includes the subjectmatter according to any one of examples 57 to 66, above.

Again, by being prismatic, optical direction-modifying particles 186 maybe selected to operatively at least one of reflect, refract, or diffractelectromagnetic radiation 118, as discussed herein. Referring generallyto FIG. 2 and particularly to, e.g., FIG. 14, system 200 furthercomprises resin supply 206, configured to provide additional resin 125to be applied to at least one of (i) precursor prepreg tow 208,dispensed from prepreg-tow supply 202, (ii) the individual ones ofelongate filaments 104, at least partially covered with resin 124, orsubsets 214 of elongate filaments 104, at least partially covered withresin 124, originating from prepreg-tow separator 210, (iii) at leastone full-length optical waveguide 102, dispensed fromfull-length-optical-waveguide supply 204, or (iv) derivative prepreg tow209, originating from combiner 212, such that elongate filaments 104 andat least one full-length optical waveguide 102 in derivative prepreg tow209 are covered with resin 124 and additional resin 125.Optical-direction-modifier supply 216 and resin supply 206 together formcombined supply 222, configured to dispense optical direction modifiers123 together with additional resin 125. The preceding subject matter ofthis paragraph characterizes example 68 of the present disclosure,wherein example 68 also includes the subject matter according to any oneof examples 49 to 67, above.

That is, combined supply 222 may dispense optical direction modifiers123 in a volume of additional resin 125. Stated differently, opticaldirection modifiers 123 may be suspended within additional resin 125. Byusing combined supply 222, even dispersion of optical directionmodifiers 123 may be ensured, and system 200 may be constructed at alower cost. For example, combined supply 222 may spray or mistadditional resin 125 and optical direction modifiers 123 together toapply them to elongate filaments 104, or elongate filaments 104 may bepulled through a bath of additional resin 125 with optical directionmodifiers 123 suspended therein.

Referring generally to, e.g., FIGS. 13 and 14, and particularly to FIG.18, method 300 of creating feedstock line 100 for additive manufacturingof object 136 is disclosed. Feedstock line 100 has a feedstock-linelength. Method 300 comprises a step of (block 302) separating precursorprepreg tow 208, comprising elongate filaments 104 and resin 124,covering elongate filaments 104, into individual ones of elongatefilaments 104, at least partially covered with resin 124, or intosubsets 214 of elongate filaments 104, at least partially covered withresin 124. Each of subsets 214 comprises a plurality of elongatefilaments 104. Method 300 also comprises a step of (block 304) combiningthe individual ones of elongate filaments 104, at least partiallycovered with resin 124, and at least one full-length optical waveguide102 or subsets 214 of elongate filaments 104, at least partially coveredwith resin 124, and at least one full-length optical waveguide 102 intoderivative prepreg tow 209 so that each of elongate filaments 104 and atleast one full-length optical waveguide 102 extend along all of thefeedstock-line length and at least one full-length optical waveguide 102is interspersed among elongate filaments 104. Method 300 furthercomprises a step of (block 306) heating at least one of (block 308)resin 124 in precursor prepreg tow 208 prior to separating precursorprepreg tow 208 into the individual ones of elongate filaments 104, atleast partially covered with resin 124, or into subsets 214 of elongatefilaments 104, at least partially covered with resin 124, to a firstthreshold temperature to facilitate separating precursor prepreg tow802; (block 310) resin 124, at least partially covering the individualones of elongate filaments 104 or subsets 214 of elongate filaments 104following separating precursor prepreg tow 208 into the individual onesof elongate filaments 104, at least partially covered with resin 124, orinto subsets 214 of elongate filaments 104, at least partially coveredwith resin 124, and prior to combining the individual ones of elongatefilaments 104, at least partially covered with resin 124, and at leastone full-length optical waveguide 102 or subsets 214 of elongatefilaments 104, at least partially covered with resin 124, and at leastone full-length optical waveguide 102 into derivative prepreg tow 209,to a second threshold temperature to cause wet-out of at least onefull-length optical waveguide 102 and elongate filaments 104 inderivative prepreg tow 209 by resin 124; or (block 312) resin 124, atleast partially covering elongate filaments 104 in derivative prepregtow 209, to a third threshold temperature to cause wet-out of at leastone full-length optical waveguide 102 and elongate filaments 104 inderivative prepreg tow 209 by resin 124. The preceding subject matter ofthis paragraph characterizes example 69 of the present disclosure.

As discussed in connection with system 200, creating feedstock line 100from precursor prepreg tow 208 permits the use of off-the-shelf prepregreinforcement fiber tows. By separating precursor prepreg tow 208 intoindividual ones of elongate filaments 104 or into subsets 214 ofelongate filaments 104, at least one full-length optical waveguide 102may be operatively interspersed with elongate filaments 104. Heatingresin 124 facilitates one or both of separation of precursor prepreg tow208 or wetting-out of elongate filaments 104 and at least onefull-length optical waveguide 102 in derivative prepreg tow 209.

Referring generally to, e.g., FIGS. 13 and 14, according to method 300,elongate filaments 104 are opaque to electromagnetic radiation 118. Thepreceding subject matter of this paragraph characterizes example 70 ofthe present disclosure, wherein example 70 also includes the subjectmatter according to example 69, above.

Again, elongate filaments 104 that are opaque to electromagneticradiation 118 may be well suited for inclusion in feedstock line 100, asat least one full-length optical waveguide 102 operatively will receiveelectromagnetic radiation 118 and disperse it into the shadows ofelongate filaments 104 when feedstock line 100 is being used toadditively manufacture object 136 with in situ curing thereof.

Referring generally to, e.g., FIGS. 2 and 9-12, according to method 300,at least one full-length optical waveguide 102 comprises full-lengthoptical core 110. Full-length optical core 110 comprises firstfull-length-optical-core end face 112, second full-length-optical-coreend face 114, opposite first full-length-optical-core end face 112, andfull-length peripheral surface 116, extending between firstfull-length-optical-core end face 112 and secondfull-length-optical-core end face 114. At least one full-length opticalwaveguide 102 is configured such that when electromagnetic radiation 118enters full-length optical core 110 via at least one of firstfull-length-optical-core end face 112, second full-length-optical-coreend face 114, or full-length peripheral surface 116, at least a portionof electromagnetic radiation 118 exits full-length optical core 110 viafull-length peripheral surface 116. The preceding subject matter of thisparagraph characterizes example 71 of the present disclosure, whereinexample 71 also includes the subject matter according to example 69 or70, above.

Again, when feedstock line 100 is used to additively manufacture object136 with in situ curing thereof (i.e., with electromagnetic radiation118 entering full-length optical core 110), at least a portion ofelectromagnetic radiation 118 will be emitted from full-length opticalcore 110 at a position that is spaced-apart from where it enteredfull-length optical core 110. As a result, electromagnetic radiation ismay be dispersed throughout interior volume 182 of feedstock line 100for operative irradiation of resin 124.

Referring generally to, e.g., FIGS. 2 and 9-12, according to method 300,at least one full-length optical waveguide 102 is configured such thatwhen electromagnetic radiation 118 enters first full-length-optical-coreend face 112 of full-length optical core 110, an initial portion ofelectromagnetic radiation 118 exits full-length optical core 110 viafull-length peripheral surface 116 and a final portion ofelectromagnetic radiation 118, remaining in full-length optical core 110after the initial portion of electromagnetic radiation 118 exitsfull-length optical core 110, exits full-length optical core 110 viasecond full-length-optical-core end face 114. The preceding subjectmatter of this paragraph characterizes example 72 of the presentdisclosure, wherein example 72 also includes the subject matteraccording to example 71, above.

As discussed, in some examples of feedstock line 100, if electromagneticradiation 118 enters first full-length-optical-core end face 112, itwill exit both full-length peripheral surface 116 and secondfull-length-optical-core end face 114, as opposed, for example, toelectromagnetic radiation 118 being fully emitted via full-lengthperipheral surface 116. Such examples of feedstock line 100 are wellsuited for additive manufacturing systems and methods in whichelectromagnetic radiation 118 is directed at firstfull-length-optical-core end face 112 as feedstock line 100 is beingconstructed and as object 136 is being manufactured.

Referring generally to, e.g., FIGS. 2 and 9-12, according to method 300,at least one full-length optical waveguide 102 is configured such thatthe initial portion of electromagnetic radiation 118, which exitsfull-length optical core 110 via full-length peripheral surface 116, isgreater than or equal to the final portion of electromagnetic radiation118, which exits full-length optical core 110 via secondfull-length-optical-core end face 114. The preceding subject matter ofthis paragraph characterizes example 73 of the present disclosure,wherein example 73 also includes the subject matter according to example72, above.

Again, in such configurations of full-length optical waveguide 102, itis ensured that a desired amount of electromagnetic radiation 118 exitsfull-length optical core 110 via full-length peripheral surface 116 tooperatively cure resin 124 among elongate filaments 104 within interiorvolume 182 of feedstock line 100 when feedstock line 100 is used toadditively manufacture object 136.

Referring generally to, e.g., FIGS. 2 and 9-11, according to method 300,full-length optical core 110 has a full-length-optical-core refractiveindex. At least one full-length optical waveguide 102 further comprisesfull-length-optical-core cladding 154, at least partially coveringfull-length optical core 110. Full-length-optical-core cladding 154comprises at least first full-length-optical-core cladding resin 156,having a full-length-optical-core first-cladding-resin refractive index.Full-length-optical-core cladding 154 is non-uniform along at least onefull-length optical waveguide 102. The full-length-optical-corerefractive index is greater than the full-length-optical-corefirst-cladding-resin refractive index. The preceding subject matter ofthis paragraph characterizes example 74 of the present disclosure,wherein example 74 also includes the subject matter according to any oneof examples 71 to 73, above.

Again, by full-length-optical-core cladding 154 being non-uniform alongthe length of the full-length optical waveguide, electromagneticradiation 118 is permitted to exit full-length optical core 110 viafull-length peripheral surface 116. Moreover, by firstfull-length-optical-core cladding resin 156 having a refractive indexthat is less than that of full-length optical core 110, electromagneticradiation 118, upon entering full-length optical core 110, is trappedwithin full-length optical core 110 other than the regions where firstfull-length-optical-core cladding resin 156 is not present. As a result,full-length optical waveguide 102 may be constructed to provide adesired amount of electromagnetic radiation 118, exiting variouspositions along full-length peripheral surface 116, such as to ensure adesired amount of electromagnetic radiation 118, penetrating the shadowsof elongate filaments 104 when feedstock line 100 is used to additivelymanufacture object 136.

Referring generally to, e.g., FIGS. 2, 10, and 11, according to method300, full-length peripheral surface 116 hasfull-length-peripheral-surface regions 127 devoid of firstfull-length-optical-core cladding resin 156. Full-length-optical-corecladding 154 further comprises second full-length-optical-core claddingresin 158, having a full-length-optical-core second-cladding-resinrefractive index. Second full-length-optical-core cladding resin 158covers full-length-peripheral-surface regions 127 of full-lengthperipheral surface 116. The full-length-optical-coresecond-cladding-resin refractive index is greater than thefull-length-optical-core first-cladding-resin refractive index. Thepreceding subject matter of this paragraph characterizes example 75 ofthe present disclosure, wherein example 75 also includes the subjectmatter according to example 74, above.

Again, by covering full-length-peripheral-surface regions 127 withsecond full-length-optical-core cladding resin 158, a desired refractiveindex thereof may be selected to optimize how electromagnetic radiation118 exits full-length peripheral surface 116. Additionally oralternatively, with full-length-peripheral-surface regions 127 coveredwith second full-length-optical-core cladding resin 158, the integrityof first full-length-optical-core cladding resin 156 may be ensured,such that it does not peel or break off during storage of at least onefull-length optical waveguide 102 and during implementation of method300.

Referring generally to, e.g., FIGS. 2 and 11, according to method 300,second full-length-optical-core cladding resin 158 also covers firstfull-length-optical-core cladding resin 156. The preceding subjectmatter of this paragraph characterizes example 76 of the presentdisclosure, wherein example 76 also includes the subject matteraccording to example 75, above.

As discussed, full-length optical waveguides, such as according toexample 76, may be more easily manufactured, in that full-length opticalcore 110 with first full-length-optical-core cladding resin 156 simplymay be fully coated with second full-length-optical-core cladding resin158. Additionally or alternatively, the integrity of full-length opticalwaveguides may be maintained during storage thereof and duringimplementation of method 300.

Referring generally to, e.g., FIGS. 2, 10, and 11, according to method300, resin 124 has a resin refractive index. The resin refractive indexis greater than the full-length-optical-core second-cladding-resinrefractive index. The preceding subject matter of this paragraphcharacterizes example 77 of the present disclosure, wherein example 77also includes the subject matter according to example 75 or 76, above.

As discussed, because second full-length-optical-core cladding resin 158has a refractive index less than that of resin 124, electromagneticradiation 118 will be permitted to exit second full-length-optical-corecladding resin 158 to penetrate and cure resin 124 when feedstock line100 is used to additively manufacture object 136.

Referring generally to, e.g., FIGS. 2 and 12, according to method 300,full-length peripheral surface 116 has a surface roughness that isselected such that when electromagnetic radiation 118 enters full-lengthoptical core 110 via at least one of first full-length-optical-core endface 112, second full-length-optical-core end face 114, or full-lengthperipheral surface 116, at least a portion of electromagnetic radiation118 exits full-length optical core 110 via full-length peripheralsurface 116. The preceding subject matter of this paragraphcharacterizes example 78 of the present disclosure, wherein example 78also includes the subject matter according to any one of examples 71 to75, above.

As discussed, rather than relying on refractive-index properties of acladding to ensure desired dispersal of electromagnetic radiation 118from full-length optical core 110 via full-length peripheral surface116, the surface roughness of full-length peripheral surface 116 isselected such that electromagnetic radiation 118 exits full-lengthoptical core 110 at desired amounts along the length of full-lengthperipheral surface 116. For example, the surface roughness may createregions of internal reflection of electromagnetic radiation 118 withinfull-length optical core 110 and may create regions whereelectromagnetic radiation 118 is permitted to escape full-length opticalcore 110.

Referring generally to, e.g., FIGS. 2 and 12, according to method 300,at least one full-length optical waveguide 102 is devoid of any claddingthat covers full-length optical core 110. The preceding subject matterof this paragraph characterizes example 79 of the present disclosure,wherein example 79 also includes the subject matter according to example78, above.

As discussed, full-length optical waveguides without any cladding may beless expensive to manufacture than full-length optical waveguides withcladding. Additionally, the difference of refractive indexes between acladding and resin 124 need not be taken into account when selectingresin 124 for feedstock line 100.

Referring generally to, e.g., FIGS. 13 and 14, and particular to FIG.18, method 300 further comprises a step of (block 314) applyingadditional resin 125 to cover elongate filaments 104 and at least onefull-length optical waveguide 102 such that elongate filaments 104 andat least one full-length optical waveguide 102 are covered by resin 124and additional resin 125 in derivative prepreg tow 209. The precedingsubject matter of this paragraph characterizes example 80 of the presentdisclosure, wherein example 80 also includes the subject matteraccording to any one of examples 69 to 79, above.

As discussed, by applying additional resin 125 to elongate filaments 104and full-length optical waveguide(s), full wet-out of elongate filaments104 and full-length optical waveguide(s) may be achieved in feedstockline 100.

Referring generally to, e.g., FIGS. 13 and 14, and particularly to FIG.18, according to method 300, (block 314) additional resin 125 is appliedto cover elongate filaments 104 and at least one full-length opticalwaveguide 102, such that elongate filaments 104 and at least onefull-length optical waveguide 102 are covered by resin 124 andadditional resin 125 in derivative prepreg tow 209, at least one ofbefore or after (block 302) separating precursor prepreg tow 208 intothe individual ones of elongate filaments 104, at least partiallycovered with resin 124, or into subsets 214 of elongate filaments 104,at least partially covered with resin 124. The preceding subject matterof this paragraph characterizes example 81 of the present disclosure,wherein example 81 also includes the subject matter according to example80, above.

In some implementations of method 300, applying additional resin 125before precursor prepreg tow 208 is separated enables a correspondingsystem (e.g., system 200 herein) to regulate the amount of additionalresin 125 on each individual one of elongate filaments 104 or subset 214of elongate filaments 104. For example, when a screen or mesh is used toseparate precursor prepreg tow 208, the screen or mesh may effectivelyscrape away excess resin 124 and additional resin 125 leaving only adesired amount on each individual one of elongate filaments 104 orsubset 214 of elongate filaments 104 for subsequent combination withfull-length optical waveguide(s) to create feedstock line 100.

On the other hand, in some implementations of method 300, applyingadditional resin 125 after precursor prepreg tow 208 is separatedenables a sufficient amount of additional resin 125 to fully wet, withresin 124, elongate filaments 104 and full-length optical waveguide(s).

In some implementations of method 300, additional resin 125 may beapplied both before and after precursor prepreg tow 208 is separated.

Referring generally to, e.g., FIGS. 13 and 14, and particularly to FIG.18, according to method 300, (block 314) additional resin 125 is appliedto cover elongate filaments 104 and at least one full-length opticalwaveguide 102, such that elongate filaments 104 and at least onefull-length optical waveguide 102 are covered by resin 124 andadditional resin 125 in derivative prepreg tow 209, at least one ofbefore or after (block 304) combining the individual ones of elongatefilaments 104, at least partially covered with resin 124, or subsets 214of elongate filaments 104, at least partially covered with resin 124,and at least one full-length optical waveguide 102 into derivativeprepreg tow 209. The preceding subject matter of this paragraphcharacterizes example 82 of the present disclosure, wherein example 82also includes the subject matter according to example 80 or 81, above.

In some implementations of method 300, applying additional resin 125before elongate filaments 104 and full-length optical waveguide 102 arecombined enables a sufficient amount of resin 124 and additional resin125 to fully wet elongate filaments 104 and full-length opticalwaveguide(s).

In some implementations of method 300, applying additional resin 125after elongate filaments 104 and full-length optical waveguide(s) arecombined into derivative prepreg tow 209 ensures that feedstock line 100has the overall desired amount of resin 124 and additional resin 125therein.

In some implementations of method 300, additional resin 125 may beapplied both before and after elongate filaments 104 and full-lengthoptical waveguide(s) are combined.

Referring generally to, e.g., FIGS. 13 and 14, and particularly to FIG.18, according to method 300, the step of (block 302) separatingprecursor prepreg tow 208 into individual ones of elongate filaments104, at least partially covered with resin 124, or into subsets 214 ofelongate filaments 104, at least partially covered with resin 124,comprises (block 316) imparting a first electrical charge to elongatefilaments 104 or to resin 124. Also, the step of (block 314) applyingadditional resin 125 to cover elongate filaments 104 and at least onefull-length optical waveguide 102, such that elongate filaments 104 andat least one full-length optical waveguide 102 are covered by resin 124and additional resin 125 in derivative prepreg tow 209, comprises (block318) imparting a second electrical charge to additional resin 125. Thesecond electrical charge and the first electrical charge have oppositesigns. The preceding subject matter of this paragraph characterizesexample 83 of the present disclosure, wherein example 83 also includesthe subject matter according to any one of examples 80 to 82, above.

As discussed in connection with system 200, by imparting a firstelectrical charge to elongate filaments 104 or resin 124 and byimparting a second opposite charge to additional resin 125 as it isapplied to elongate filaments 104 and resin 124, additional resin 125will be electrostatically attracted to elongate filaments 104.

Referring generally to, e.g., FIGS. 13 and 14, and particularly to FIG.18, according to method 300, the step of (block 304) combining theindividual ones of elongate filaments 104, at least partially coveredwith resin 124, and at least one full-length optical waveguide 102 orsubsets 214 of elongate filaments 104, at least partially covered withresin 124, and at least one full-length optical waveguide 102 intoderivative prepreg tow 209 comprises at least one of twisting, weaving,or braiding the individual ones of elongate filaments 104, at leastpartially covered with resin 124, and at least one full-length opticalwaveguide 102, or subsets 214 of elongate filaments 104, at leastpartially covered with resin 124, and at least one full-length opticalwaveguide 102, into derivative prepreg tow 209. The preceding subjectmatter of this paragraph characterizes example 84 of the presentdisclosure, wherein example 84 also includes the subject matteraccording to any one of examples 69 to 83, above.

Again, by being twisted with, woven with, or braided with elongatefilaments 104, at least one full-length optical waveguide 102 isinterspersed with elongate filaments 104 so that electromagneticradiation 118, exiting at least one full-length optical waveguide 102,is delivered to regions of interior volume 182 that are in the shadowsof elongate filaments 104 when feedstock line 100 is used to additivelymanufacture object 136.

Referring generally to, e.g., FIGS. 2 and 14, and particularly to FIG.18, method 300 further comprises a step of (block 322) applying opticaldirection modifiers 123 to the individual ones of elongate filaments104, at least partially covered with resin 124, or to subsets 214 ofelongate filaments 104, at least partially covered with resin 124.According to method 300, the step of (block 304) combining theindividual ones of elongate filaments 104, at least partially coveredwith resin 124, and at least one full-length optical waveguide 102 orsubsets 214 of elongate filaments 104, at least partially covered withresin 124, and at least one full-length optical waveguide 102 intoderivative prepreg tow 209 comprises (block 324) combining opticaldirection modifiers 123 with at least one full-length optical waveguide102 and the individual ones of elongate filaments 104, at leastpartially covered with resin 124, or subsets 214 of elongate filaments104, at least partially covered with resin 124, into derivative prepregtow 209 so that optical direction modifiers 123 are interspersed amongelongate filaments 104. Each of optical direction modifiers 123 hasouter surface 184. Each of optical direction modifiers 123 is configuredsuch that when electromagnetic radiation 118 strikes outer surface 184from a first direction, at least a portion of electromagnetic radiation118 departs outer surface 184 in a second direction that is at an angleto the first direction. The preceding subject matter of this paragraphcharacterizes example 85 of the present disclosure, wherein example 85also includes the subject matter according to any one of examples 69 to84, above.

As discussed, by applying optical direction modifiers 123 to elongatefilaments 104 to become part of feedstock line 100, additionaldispersion of electromagnetic radiation 118 within interior volume 182for irradiation of resin 124 therein may be achieved when feedstock line100 is used to additively manufacture object 136. Moreover, again, bybeing shorter than full-length optical waveguides, optical directionmodifiers 123 may more easily extend among elongate filaments 104 withinderivative prepreg tow 209. Not only may optical direction modifiers 123serve to disperse, or scatter, electromagnetic radiation 118 into theshadows of elongate filaments 104, but they also may serve to redirectelectromagnetic radiation 118 to at least one full-length opticalwaveguide 102 for penetration into the shadows of elongate filaments 104by at least one full-length optical waveguide 102.

Referring generally to, e.g., FIGS. 9-12, according to method 300,optical direction modifiers 123 comprise partial-length opticalwaveguides 122. Each of partial-length optical waveguides 122 comprisespartial-length optical core 138. Partial-length optical core 138 of eachof partial-length optical waveguides 122 comprises firstpartial-length-optical-core end face 140, secondpartial-length-optical-core end face 142, opposite firstpartial-length-optical-core end face 140, and partial-length peripheralsurface 144, extending between first partial-length-optical-core endface 140 and second partial-length-optical-core end face 142. Each ofpartial-length optical waveguides 122 is configured such that whenelectromagnetic radiation 118 enters partial-length optical core 138 viaat least one of first partial-length-optical-core end face 140, secondpartial-length-optical-core end face 142, or partial-length peripheralsurface 144, at least a portion of electromagnetic radiation 118 exitspartial-length optical core 138 via partial-length peripheral surface144. The preceding subject matter of this paragraph characterizesexample 86 of the present disclosure, wherein example 86 also includesthe subject matter according to example 85, above.

In some examples of method 300, optical direction modifiers 123 aresimilar in construction to full-length optical waveguides but areshorter in length.

Referring generally to, e.g., FIGS. 9-11, according to method 300,partial-length optical core 138 has a partial-length-optical-corerefractive index. Each of partial-length optical waveguides 122 furthercomprises partial-length-optical-core cladding 160, at least partiallycovering partial-length optical core 138. Partial-length-optical-corecladding 160 comprises at least first partial-length-optical-corecladding resin 162, having a partial-length-optical-corefirst-cladding-resin refractive index. Partial-length-optical-corecladding 160 is non-uniform along each of partial-length opticalwaveguides 122. Partial-length-optical-core refractive index is greaterthan the partial-length-optical-core first-cladding-resin refractiveindex. The preceding subject matter of this paragraph characterizesexample 87 of the present disclosure, wherein example 87 also includesthe subject matter according to example 86, above.

Again, similar to full-length optical waveguide 102, bypartial-length-optical-core cladding 160 being non-uniform along thelength of partial-length optical waveguides 122, electromagneticradiation 118 is permitted to exit partial-length optical core 138 viapartial-length peripheral surface 144. Moreover, by firstpartial-length-optical-core cladding resin 162 having a refractive indexthat is less than that of partial-length optical core 138,electromagnetic radiation 118, upon entering partial-length optical core138, is trapped within partial-length optical core 138 other than theregions where first partial-length-optical-core cladding resin 162 isnot present. As a result, partial-length optical waveguides 122 may beconstructed to provide a desired amount of electromagnetic radiation118, exiting various positions along partial-length peripheral surface144, such as to ensure a desired amount of electromagnetic radiation118, penetrating the shadows of elongate filaments 104 when feedstockline 100 is being used to additively manufacture object 136.

Referring generally to, e.g., FIGS. 10 and 11, according to method 300,partial-length peripheral surface 144 of partial-length optical core 138of each of partial-length optical waveguides 122 haspartial-length-peripheral-surface regions 129 devoid of firstpartial-length-optical-core cladding resin 162.Partial-length-optical-core cladding 160 further comprises secondpartial-length-optical-core cladding resin 164, having apartial-length-optical-core second-cladding-resin refractive index.Second partial-length-optical-core cladding resin 164 coverspartial-length-peripheral-surface regions 129 of partial-lengthperipheral surface 144. The partial-length-optical-coresecond-cladding-resin refractive index is greater than thepartial-length-optical-core first-cladding-resin refractive index. Thepreceding subject matter of this paragraph characterizes example 88 ofthe present disclosure, wherein example 88 also includes the subjectmatter according to example 87, above.

As discussed, by covering partial-length-peripheral-surface regions 129with second partial-length-optical-core cladding resin 164, a desiredrefractive index thereof may be selected to optimize how electromagneticradiation 118 exits partial-length peripheral surface 144. Additionallyor alternatively, with partial-length-peripheral-surface regions 129covered with second partial-length-optical-core cladding resin 164, theintegrity of first partial-length-optical-core cladding resin 162 may beensured, such that it does not peel or break off during storage ofpartial-length optical waveguides 122 and during implementation ofmethod 300.

Referring generally to, e.g., FIG. 11, according to method 300, secondpartial-length-optical-core cladding resin 164 also covers firstpartial-length-optical-core cladding resin 162. The preceding subjectmatter of this paragraph characterizes example 89 of the presentdisclosure, wherein example 89 also includes the subject matteraccording to example 88, above.

As discussed, partial-length optical waveguides 122, such as accordingto example 89, may be more easily manufactured, in that partial-lengthoptical core 138 with first partial-length-optical-core cladding resin162 simply may be fully coated with second partial-length-optical-corecladding resin 164. Additionally or alternatively, the integrity ofpartial-length optical waveguides 122 may be maintained during storagethereof and during implementation of method 300.

Referring generally to, e.g., FIGS. 10 and 11, and particularly to FIG.18, according to method 300, resin 124 has a resin refractive index. Theresin refractive index is greater than the partial-length-optical-coresecond-cladding-resin refractive index. The preceding subject matter ofthis paragraph characterizes example 90 of the present disclosure,wherein example 90 also includes the subject matter according to example88 or 89, above.

Again, because second partial-length-optical-core cladding resin 164 hasa refractive index less than that of resin 124, electromagneticradiation 118 will be permitted to exit secondpartial-length-optical-core cladding resin 164 to penetrate and cureresin 124 when feedstock line 100 is being used to additivelymanufacture object 136.

Referring generally to, e.g., FIG. 12, according to method 300,partial-length peripheral surface 144 of partial-length optical core 138of each of partial-length optical waveguides 122 has a surface roughnessthat is selected such that when electromagnetic radiation 118 enterspartial-length optical core 138 via at least one of firstpartial-length-optical-core end face 140, secondpartial-length-optical-core end face 142, or partial-length peripheralsurface 144, at least a portion of electromagnetic radiation 118 exitspartial-length optical core 138 via partial-length peripheral surface144. The preceding subject matter of this paragraph characterizesexample 91 of the present disclosure, wherein example 91 also includesthe subject matter according to example 86, above.

As discussed, rather than relying on refractive-index properties of acladding to ensure desired dispersal of electromagnetic radiation 118from partial-length optical core 138 via partial-length peripheralsurface 144, the surface roughness of partial-length peripheral surface144 is selected such that electromagnetic radiation 118 exitspartial-length optical core 138 at desired amounts along the length ofpartial-length peripheral surface 144. Again, the surface roughness maycreate regions of internal reflection of electromagnetic radiation 118within partial-length optical core 138 and may create regions whereelectromagnetic radiation 118 is permitted to escape partial-lengthoptical core 138.

Referring generally to, e.g., FIG. 12, according to method 300, each ofpartial-length optical waveguides 122 is devoid of any cladding thatcovers partial-length optical core 138. The preceding subject matter ofthis paragraph characterizes example 92 of the present disclosure,wherein example 92 also includes the subject matter according to example91, above.

As discussed, partial-length optical waveguides 122 without any claddingmay be less expensive to manufacture than partial-length opticalwaveguides 122 with cladding. Additionally, the difference of refractiveindexes between a cladding and resin 124 need not be taken into accountwhen selecting resin 124 for feedstock line 100.

Referring generally to, e.g., FIGS. 15-17, according to method 300,optical direction modifiers 123 comprise optical direction-modifyingparticles 186. Optical direction-modifying particles 186 are configuredto at least one of reflect, refract, diffract, or Rayleigh-scatterelectromagnetic radiation 118, incident on outer surface 184 of any oneof optical direction-modifying particles 186, to disperseelectromagnetic radiation 118. The preceding subject matter of thisparagraph characterizes example 93 of the present disclosure, whereinexample 93 also includes the subject matter according to any one ofexamples 85 to 92, above.

Again, inclusion of optical direction-modifying particles 186 that atleast one of reflect, refract, diffract, or Rayleigh-scatterelectromagnetic radiation 118 provides for further dispersion ofelectromagnetic radiation 118 within interior volume 182 for irradiationof resin 124 therein when feedstock line 100 is being used to additivelymanufacture object 136. Moreover, because they are particles, opticaldirection-modifying particles 186 more easily are interspersed amongelongate filaments 104 when applied thereto. In addition, in someexamples of feedstock line 100, they may be generally uniformly spacedthroughout resin 124 within interior volume 182 and effectively scatterelectromagnetic radiation 118 throughout interior volume 182 topenetrate among elongate filaments 104 and into the shadows cast byelongate filaments 104 when feedstock line 100 is being used toadditively manufacture object 136. In other examples of feedstock line100, optical direction-modifying particles 186 may have a gradient ofconcentration within interior volume 182.

Referring generally to, e.g., FIGS. 6, 7, and 15-17, according to method300, each of elongate filaments 104 has a minimum outer dimension. Eachof optical direction-modifying particles 186 has a maximum outerdimension that is less than one-eighth the minimum outer dimension ofany one of elongate filaments 104. The preceding subject matter of thisparagraph characterizes example 94 of the present disclosure, whereinexample 94 also includes the subject matter according to example 93,above.

Again, by having a maximum outer dimension that is less than one-eighththe minimum outer dimension of elongate filaments 104, opticaldirection-modifying particles 186 are easily dispersed between elongatefilaments 104. Moreover, optical direction-modifying particles 186 mayeasily flow with resin 124 to operatively disperse opticaldirection-modifying particles 186 throughout feedstock line 100,including into the shadows of elongate filaments 104.

Referring generally to, e.g., FIGS. 15-17, according to method 300, eachof optical direction-modifying particles 186 has a maximum outerdimension that is less than 1000 nm, 500 nm, 250 nm, or 200 nm. Thepreceding subject matter of this paragraph characterizes example 95 ofthe present disclosure, wherein example 95 also includes the subjectmatter according to example 93 or 94, above.

As discussed, typical reinforcement fibers for composite materials oftenhave a diameter in the range of 5 to 8 microns. By having a maximumouter dimension that is less than 1000 nm (1 micron), 500 nm (0.5micron), 250 nm (0.25 micron), or 200 nm (0.200 micron), opticaldirection-modifying particles 186 easily extend among typical sizes ofelongate filaments 104. Moreover, optical direction-modifying particles186 may easily flow with resin 124 to operatively disperse opticaldirection-modifying particles 186 throughout feedstock line 100,including into the shadows of elongate filaments 104.

Referring generally to, e.g., FIGS. 15-17, according to method 300,electromagnetic radiation 118 has a wavelength. Each of opticaldirection-modifying particles 186 has a minimum outer dimension that isgreater than one-fourth the wavelength of electromagnetic radiation 118.The preceding subject matter of this paragraph characterizes example 96of the present disclosure, wherein example 96 also includes the subjectmatter according to any one of examples 93 to 95, above.

Again, selecting a minimum outer dimension of opticaldirection-modifying particles 186 that is greater than one-fourth thewavelength of electromagnetic radiation 118 that will be used whenadditively manufacturing object 136 ensures that opticaldirection-modifying particles 186 will have the intended effect ofcausing electromagnetic radiation 118 to reflect, refract, or diffractupon hitting optical direction-modifying particles 186.

Referring generally to, e.g., FIGS. 15-17, according to method 300, eachof optical direction-modifying particles 186 has a minimum outerdimension that is greater than or equal to 50 nm or that is greater thanor equal to 100 nm. The preceding subject matter of this paragraphcharacterizes example 97 of the present disclosure, wherein example 97also includes the subject matter according to any one of examples 93 to96, above.

As discussed, ultra-violet light having a wavelength of about 400 nm isoften used in connection with ultra-violet photopolymers. Accordingly,when resin 124 comprises or consists of a photopolymer, opticaldirection-modifying particles 186 having a minimum outer dimension thatis greater than or equal to 100 nm ensures that opticaldirection-modifying particles 186 will have the intended effect ofcausing electromagnetic radiation 118 to reflect, refract, or diffractupon hitting optical direction-modifying particles 186. However, inother examples, a minimum outer dimension as low as 50 nm may beappropriate.

Referring generally to, e.g., FIGS. 1, 6, and 7, according to method300, in feedstock line 100, optical direction-modifying particles 186comprise less than 10% by weight of resin 124, less than 5% by weight ofresin 124, or less than 1% by weight of resin 124. The preceding subjectmatter of this paragraph characterizes example 98 of the presentdisclosure, wherein example 98 also includes the subject matteraccording to any one of examples 93 to 97, above.

As discussed, by limiting optical direction-modifying particles 186 tothe referenced threshold percentages, resin 124 will operatively flowamong elongate filaments 104 when elongate filaments 104, at least onefull-length optical waveguide 102, and optical direction-modifyingparticles 186 are being combined to create feedstock line 100. Inaddition, desired properties of resin 124, feedstock line 100, andultimately object 136 will not be negatively impacted by the presence ofoptical direction-modifying particles 186.

Referring generally to, e.g., FIGS. 15-17, according to method 300,outer surfaces 184 of at least some of optical direction-modifyingparticles 186 are faceted. The preceding subject matter of thisparagraph characterizes example 99 of the present disclosure, whereinexample 99 also includes the subject matter according to any one ofexamples 93 to 98, above.

Again, by being faceted, outer surfaces 184 effectively scatterelectromagnetic radiation 118.

Referring generally to, e.g., FIGS. 15-17, according to method 300,outer surfaces 184 of at least some of optical direction-modifyingparticles 186 have a surface roughness that is selected such that whenelectromagnetic radiation 118 strikes outer surfaces 184,electromagnetic radiation 118 is scattered. The preceding subject matterof this paragraph characterizes example 100 of the present disclosure,wherein example 100 also includes the subject matter according to anyone of examples 93 to 99, above.

As discussed, having a surface roughness selected to scatterelectromagnetic radiation 118 facilitates the operative irradiation ofresin 124 throughout feedstock line 100, including into the shadows ofelongate filaments 104, when feedstock line 100 is being used toadditively manufacture object 136.

Referring generally to, e.g., FIGS. 6 and 7, according to method 300,resin 124 has a resin refractive index. At least some of opticaldirection-modifying particles 186 have a particle refractive index. Theparticle refractive index is greater than or less than the resinrefractive index. The preceding subject matter of this paragraphcharacterizes example 101 of the present disclosure, wherein example 101also includes the subject matter according to any one of examples 93 to100, above.

Again, when optical direction-modifying particles 186 have a refractiveindex that is different from the refractive index of resin 124,electromagnetic radiation 118 incident upon the outer surfaces thereofwill necessarily leave the outer surfaces at a different angle, and thuswill scatter throughout resin 124, including into the shadows ofelongate filaments 104.

Referring generally to, e.g., FIG. 15, according to method 300, at leastsome of optical direction-modifying particles 186 are spherical. Thepreceding subject matter of this paragraph characterizes example 102 ofthe present disclosure, wherein example 102 also includes the subjectmatter according to any one of examples 93 to 101, above.

Again, by being spherical, optical direction-modifying particles 186easily be positioned among elongate filaments 104 and may easily flowwith resin 124 as elongate filaments 104 and optical direction-modifyingparticles 186 are being combined.

Referring generally to, e.g., FIG. 16, according to method 300, at leastsome of optical direction-modifying particles 186 are prismatic. Thepreceding subject matter of this paragraph characterizes example 103 ofthe present disclosure, wherein example 103 also includes the subjectmatter according to any one of examples 93 to 102, above.

Again, by being prismatic, optical direction-modifying particles 186 maybe selected to operatively at least one of reflect, refract, or diffractelectromagnetic radiation 118, as discussed herein.

Referring generally to FIG. 3 and particularly to, e.g., FIGS. 9-12,optical waveguide 108 is disclosed. Optical waveguide 108 comprisesoptical core 146, comprising first end face 148, second end face 150,opposite first end face 148, and peripheral surface 152, extendingbetween first end face 148 and second end face 150. Optical waveguide108 is configured such that when electromagnetic radiation 118 entersoptical core 146 via at least one of first end face 148, second end face150, or peripheral surface 152, at least a portion of electromagneticradiation 118 exits optical core 146 via peripheral surface 152. Thepreceding subject matter of this paragraph characterizes example 104 ofthe present disclosure.

Because optical waveguide 108 is configured for electromagneticradiation to enter optical core 146 via any one of first end face 148,second end face 150, or peripheral surface 152 and then exit opticalcore 146 via peripheral surface 152, optical waveguide 108 is wellsuited for inclusion in a photopolymer resin (e.g., resin 124 herein) ofa feedstock line (e.g., feedstock line 100 here) that also includesreinforcing fibers (e.g., elongate filaments 104 herein) and that isused to additively manufacture an object (e.g., object 136 herein). Morespecifically, inclusion of at least one optical waveguide 108 in such afeedstock line facilitates penetration of electromagnetic radiation 118into the interior volume of the feedstock line for irradiation of theresin, despite regions of the resin being in the shadows of thereinforcing fibers cast by the direct (i.e., line-of-sight) applicationof electromagnetic radiation 118. In other words, even whenelectromagnetic radiation 118 is shielded from directly reaching allregions of the resin, at least one optical waveguide 108 will receiveelectromagnetic radiation 118 via one or more of first end face 148,second end face 150, or peripheral surface 152, and disperseelectromagnetic radiation 118 via at least peripheral surface 152 toindirectly reach regions of the resin. As a result, the feedstock linemay be more easily cured with electromagnetic radiation 118, may be moreevenly cured with electromagnetic radiation 118, may be more thoroughlycured with electromagnetic radiation 118, and/or may be more quicklycured with electromagnetic radiation 118. Such a configuration offeedstock line is particularly well suited for additive manufacturing ofthe fused filament fabrication variety, in which the feedstock line isdispensed by a print head, or nozzle, and a source of curing energy(e.g., electromagnetic radiation 118) directs the curing energy at thefeedstock line as it is being dispensed to cure the resin in situ.

Full-length optical waveguides and partial-length optical waveguides areexamples of optical waveguides, such as optical waveguide 108.

Referring generally to FIG. 3 and particularly to, e.g., FIGS. 9-12,optical waveguide 108 is configured such that when electromagneticradiation 118 enters first end face 148 of optical core 146, an initialportion of electromagnetic radiation 118 exits optical core 146 viaperipheral surface 152 and a final portion of electromagnetic radiation118, remaining in optical core 146 after the initial portion ofelectromagnetic radiation 118 exits optical core 146, exits optical core146 via second end face 150 of optical core 146. The preceding subjectmatter of this paragraph characterizes example 105 of the presentdisclosure, wherein example 105 also includes the subject matteraccording to example 104, above.

That is, when electromagnetic radiation 118 enters first end face 148,it will exit both peripheral surface 152 and second end face 150, asopposed, for example, to electromagnetic radiation 118 being fullyemitted via peripheral surface 152. Such examples of optical waveguide108 are well suited for inclusion in feedstock lines with additivemanufacturing systems and methods in which electromagnetic radiation 118is directed at first end face 148 as the feedstock line is beingconstructed and as an object is being manufactured. That is, an additivemanufacturing system may be configured to construct a feedstock linewhile the object is being manufactured from the feedstock line, andwhile electromagnetic radiation 118 is entering first end face 148.Because electromagnetic radiation 118 exits not only peripheral surface152, but also second end face 150, it is ensured that sufficientelectromagnetic radiation 118 travels the full length of opticalwaveguide 108 to operatively cure the resin of the feedstock line thatis in the shadows of the reinforcing fibers.

Referring generally to FIG. 3 and particularly to, e.g., FIGS. 9-12,optical waveguide 108 is configured such that the initial portion ofelectromagnetic radiation 118 that exits optical core 146 via peripheralsurface 152 is greater than or equal to the final portion ofelectromagnetic radiation 118 that exits optical core 146 via second endface 150 of optical core 146. The preceding subject matter of thisparagraph characterizes example 106 of the present disclosure, whereinexample 106 also includes the subject matter according to example 105,above.

In such configurations, it is ensured that a desired amount ofelectromagnetic radiation 118 exits optical core 146 via peripheralsurface 152 to operatively cure the resin of a feedstock line that is inthe shadows of the reinforcing fibers, when the feedstock line isutilized by an additive manufacturing system or in an additivemanufacturing method.

Referring generally to FIG. 3 and particularly to, e.g., FIGS. 9-11,optical core 146 has an optical-core refractive index. Optical waveguide108 further comprises cladding 120, at least partially covering opticalcore 146. Cladding 120 comprises at least first resin 132, having afirst-resin refractive index. Cladding 120 is non-uniform along opticalwaveguide 108. The optical-core refractive index is greater than thefirst-resin refractive index. The preceding subject matter of thisparagraph characterizes example 107 of the present disclosure, whereinexample 107 also includes the subject matter according to any one ofexamples 104 to 106, above.

By cladding 120 being non-uniform along the length of optical waveguide108, electromagnetic radiation 118 is permitted to exit optical core 146via peripheral surface 152. Moreover, by first resin 132 having arefractive index that is less than that of optical core 146,electromagnetic radiation 118, upon entering optical core 146, istrapped within optical core 146 other than the regions where first resin132 is not present. As a result, optical waveguide 108 may beconstructed to provide a desired amount of electromagnetic radiation118, exiting various positions along peripheral surface 152, such as toensure a desired amount of electromagnetic radiation 118, penetratingthe shadows of reinforcing fibers when optical waveguide 108 is includedin a feedstock line that is used to additively manufacture an object.

Referring generally to FIG. 3 and particularly to, e.g., FIGS. 10 and11, peripheral surface 152 has regions 130 where first resin 132 doesnot contact peripheral surface 152. Cladding 120 further comprisessecond resin 134, having a second-resin refractive index. Second resin134 contacts regions 130 of peripheral surface 152. The second-resinrefractive index is greater than the first-resin refractive index. Thepreceding subject matter of this paragraph characterizes example 108 ofthe present disclosure, wherein example 108 also includes the subjectmatter according to example 107, above.

By covering regions 130 with second resin 134, a desired refractiveindex thereof may be selected to optimize how electromagnetic radiation118 exits peripheral surface 152. Additionally or alternatively, withregions 130 covered with second resin 134, the integrity of first resin132 may be ensured, such that it does not peel or break off duringstorage of optical waveguide 108 and during construction of anassociated feedstock line.

Referring generally to FIG. 3 and particularly to, e.g., FIG. 11, secondresin 134 covers first resin 132. The preceding subject matter of thisparagraph characterizes example 109 of the present disclosure, whereinexample 109 also includes the subject matter according to example 108,above.

Optical waveguides, such as optical waveguide 108, according to example109 may be more easily manufactured, in that optical core 146 with firstresin 132 simply may be fully coated with second resin 134. Additionallyor alternatively, the integrity of optical waveguides may be maintainedduring storage thereof and during construction of an associatedfeedstock line.

Referring generally to FIG. 3 and particularly to, e.g., FIG. 12,peripheral surface 152 has a surface roughness that is selected suchthat when electromagnetic radiation 118 enters optical core 146 via atleast one of first end face 148, second end face 150, or peripheralsurface 152, at least a portion of electromagnetic radiation 118 exitsoptical core 146 via peripheral surface 152. The preceding subjectmatter of this paragraph characterizes example 110 of the presentdisclosure, wherein example 110 also includes the subject matteraccording to any one of examples 104 to 106, above.

Rather than relying on refractive index properties of a cladding toensure desired dispersal of electromagnetic radiation 118 from opticalcore 146 via peripheral surface 152, the surface roughness of peripheralsurface 152 is selected such that electromagnetic radiation 118 exitsoptical core 146 at desired amounts along the length of peripheralsurface 152. For example, the surface roughness may create regions ofinternal reflection of electromagnetic radiation 118 within optical core146 and may create regions where electromagnetic radiation 118 ispermitted to escape optical core 146.

Referring generally to FIG. 3 and particularly to, e.g., FIG. 12,optical waveguide 108 is devoid of any cladding that covers optical core146. The preceding subject matter of this paragraph characterizesexample 111 of the present disclosure, wherein example 111 also includesthe subject matter according to example 110, above.

Optical waveguides without any cladding may be less expensive tomanufacture than optical waveguides with cladding. Additionally, thedifference of refractive indexes between a cladding and a resin of afeedstock line need not be taken into account when selecting the resinfor the feedstock line.

Referring generally to, e.g., FIGS. 3, 8, and 9, and particularly toFIG. 19, method 400 of modifying optical fiber 126 to create opticalwaveguide 108 is disclosed. Optical fiber 126 comprises optical core146, having an optical-core refractive index, and cladding 120,comprising at least first resin 132, having a first-resin refractiveindex that is less than the optical-core refractive index. Cladding 120covers peripheral surface 152 of optical core 146 and extends betweenfirst end face 148 and second end face 150 of optical core 146. Method400 comprises a step of (block 402) removing portions 128 of cladding120 to expose regions 130 of peripheral surface 152, such that at leasta portion of electromagnetic radiation 118, entering optical core 146via at least one of first end face 148, second end face 150, orperipheral surface 152, exits optical core 146 via regions 130 ofperipheral surface 152. The preceding subject matter of this paragraphcharacterizes example 112 of the present disclosure.

Method 400 provides an inexpensive process for creating opticalwaveguide 108. For example, an off-the-shelf cladded optical fiber maybe used as optical fiber 126, and portions 128 of cladding 120 simplymay be removed at spaced-apart regions 130 that are appropriately spacedapart to result in the desired functions of optical waveguide 108,discussed herein.

Any suitable process may be utilized to remove portion 128 of cladding120, including, for example, mechanical processes, chemical processes,thermal processes (e.g., utilizing a laser), etc.

Referring generally to, e.g., FIGS. 3 and 8-11, and particularly to FIG.19, method 400 further comprises a step of (block 404) applying secondresin 134 to contact regions 130 of peripheral surface 152. Second resin134 has a second-resin refractive index that is greater than thefirst-resin refractive index. The preceding subject matter of thisparagraph characterizes example 113 of the present disclosure, whereinexample 113 also includes the subject matter according to example 112,above.

As discussed, by covering regions 130 with second resin 134, a desiredrefractive index thereof may be selected to optimize how electromagneticradiation 118 exits peripheral surface 152. Additionally oralternatively, with regions 130 covered with second resin 134, theintegrity of first resin 132 may be ensured, such that it does not peelor break off during storage of optical waveguide 108 and duringconstruction of an associated feedstock line.

Referring generally to, e.g., FIGS. 3, 8, 9, and 11, and particularly toFIG. 19, according to method 400, the step of (block 404) applyingsecond resin 134 to contact regions 130 of peripheral surface 152comprises (block 406) covering first resin 132 with second resin 134.The preceding subject matter of this paragraph characterizes example 114of the present disclosure, wherein example 114 also includes the subjectmatter according to example 113, above.

Applying second resin 134 such that it also covers first resin 132 maybe an easier and less-expensive process than applying second resin 134only to contact and cover regions 130.

Referring generally to, e.g., FIGS. 3 and 9, and particularly to FIG.20, method 500 of modifying optical core 146 to create optical waveguide108 is disclosed. Optical core 146 comprises first end face 148, secondend face 150, opposite first end face 148, and peripheral surface 152,extending between first end face 148 and second end face 150. Method 500of comprises a step of (block 502) applying first resin 132 toperipheral surface 152 of optical core 146 so that regions 130 ofperipheral surface 152 remain uncovered by first resin 132. First resin132 has a first-resin refractive index. Optical core 146 has anoptical-core refractive index that is greater than the first-resinrefractive index. At least a portion of electromagnetic radiation 118,entering optical core 146 via at least one of first end face 148, secondend face 150, or peripheral surface 152, exits optical core 146 viaperipheral surface 152. The preceding subject matter of this paragraphcharacterizes example 115 of the present disclosure.

Method 500 provides an inexpensive process for creating opticalwaveguide 108. For example, an off-the-shelf non-cladded optical fibermay be used as optical core 146, and first resin 132 may be applied toperipheral surface 152 thereof.

Any suitable process for applying first resin 132 may be used,including, for example spraying, misting, or splattering first resin 132on peripheral surface 152, such that regions 130 of peripheral surface152 remain uncovered by first resin 132.

Referring generally to, e.g., FIGS. 3 and 9-11, and particularly to FIG.20, method 500 further comprises a step of (block 504) applying secondresin 134 to contact regions 130 of peripheral surface 152 to createwith first resin 132 cladding 120 that covers peripheral surface 152 ofoptical core 146. Second resin 134 has a second-resin refractive indexthat is greater than the first-resin refractive index. The precedingsubject matter of this paragraph characterizes example 116 of thepresent disclosure, wherein example 116 also includes the subject matteraccording to example 115, above.

Similar to method 400, by covering regions 130 with second resin 134, adesired refractive index thereof may be selected to optimize howelectromagnetic radiation 118 exits peripheral surface 152. Additionallyor alternatively, with regions 130 covered with second resin 134, theintegrity of first resin 132 may be ensured, such that it does not peelor break off during storage of optical waveguide 108 and duringconstruction of an associated feedstock line.

Referring generally to, e.g., FIGS. 3, 9, and 11, and particularly toFIG. 20, according to method 500, the step of (block 504) applyingsecond resin 134 to contact regions 130 of peripheral surface 152comprises (block 506) covering first resin 132 with second resin 134.The preceding subject matter of this paragraph characterizes example 117of the present disclosure, wherein example 117 also includes the subjectmatter according to example 116, above.

Again, applying second resin 134 such that it also covers first resin132 may be an easier and less-expensive process than applying secondresin 134 only to contact and cover regions 130.

Referring generally to, e.g., FIGS. 3 and 12, and particularly to FIG.21, method 600 of modifying optical core 146 to create optical waveguide108 is disclosed. Optical core 146 comprises first end face 148, secondend face 150, opposite first end face 148, and peripheral surface 152,extending between first end face 148 and second end face 150. Method 600comprises a step of (block 602) increasing surface roughness of all orportions of peripheral surface 152 of optical core 146 so that at leasta portion of electromagnetic radiation 118, entering optical core 146via at least one of first end face 148, second end face 150, orperipheral surface 152, exits optical core 146 via peripheral surface152. The preceding subject matter of this paragraph characterizesexample 118 of the present disclosure.

Method 600 provides an inexpensive process for creating opticalwaveguide 108. For example, an off-the-shelf non-cladded optical fibermay be used as optical core 146, and peripheral surface 152 thereof maybe roughened.

Any suitable process for increasing surface roughness of peripheralsurface may be used including, for example, mechanical processes,chemical processes, thermal processes (e.g., utilizing a laser), etc.

Referring generally to, e.g., FIGS. 3 and 12, and particularly to FIG.21, method 600 further comprises a step of (block 604) applying cladding120 to cover peripheral surface 152. Optical core 146 has anoptical-core refractive index. Cladding 120 has a cladding refractiveindex. The optical-core refractive index is less than the claddingrefractive index. The preceding subject matter of this paragraphcharacterizes example 119 of the present disclosure, wherein example 119also includes the subject matter according to example 118, above.

By applying cladding 120 to cover peripheral surface 152, the integrityof the surface roughness of peripheral surface 152 may be maintained,and by selecting a cladding refractive index that is less than theoptical-core refractive index ensures that electromagnetic radiation 118can operatively exit optical core 146 at desired locations as a resultof the surface roughness of peripheral surface 152.

Examples of the present disclosure may be described in the context ofaircraft manufacturing and service method 1100 as shown in FIG. 22 andaircraft 1102 as shown in FIG. 23. During pre-production, illustrativemethod 1100 may include specification and design (block 1104) ofaircraft 1102 and material procurement (block 1106). During production,component and subassembly manufacturing (block 1108) and systemintegration (block 1110) of aircraft 1102 may take place. Thereafter,aircraft 1102 may go through certification and delivery (block 1112) tobe placed in service (block 1114). While in service, aircraft 1102 maybe scheduled for routine maintenance and service (block 1116). Routinemaintenance and service may include modification, reconfiguration,refurbishment, etc. of one or more systems of aircraft 1102.

Each of the processes of illustrative method 1100 may be performed orcarried out by a system integrator, a third party, and/or an operator(e.g., a customer). For the purposes of this description, a systemintegrator may include, without limitation, any number of aircraftmanufacturers and major-system subcontractors; a third party mayinclude, without limitation, any number of vendors, subcontractors, andsuppliers; and an operator may be an airline, leasing company, militaryentity, service organization, and so on.

As shown in FIG. 23, aircraft 1102 produced by illustrative method 1100may include airframe 1118 with a plurality of high-level systems 1120and interior 1122. Examples of high-level systems 1120 include one ormore of propulsion system 1124, electrical system 1126, hydraulic system1128, and environmental system 1130. Any number of other systems may beincluded. Although an aerospace example is shown, the principlesdisclosed herein may be applied to other industries, such as theautomotive industry. Accordingly, in addition to aircraft 1102, theprinciples disclosed herein may apply to other vehicles, e.g., landvehicles, marine vehicles, space vehicles, etc.

Apparatus(es) and method(s) shown or described herein may be employedduring any one or more of the stages of the manufacturing and servicemethod 1100. For example, components or subassemblies corresponding tocomponent and subassembly manufacturing (block 1108) may be fabricatedor manufactured in a manner similar to components or subassembliesproduced while aircraft 1102 is in service (block 1114). Also, one ormore examples of the apparatus(es), method(s), or combination thereofmay be utilized during production stages 1108 and 1110, for example, bysubstantially expediting assembly of or reducing the cost of aircraft1102. Similarly, one or more examples of the apparatus or methodrealizations, or a combination thereof, may be utilized, for example andwithout limitation, while aircraft 1102 is in service (block 1114)and/or during maintenance and service (block 1116).

Different examples of the apparatus(es) and method(s) disclosed hereininclude a variety of components, features, and functionalities. Itshould be understood that the various examples of the apparatus(es) andmethod(s) disclosed herein may include any of the components, features,and functionalities of any of the other examples of the apparatus(es)and method(s) disclosed herein in any combination, and all of suchpossibilities are intended to be within the scope of the presentdisclosure.

Many modifications of examples set forth herein will come to mind to oneskilled in the art to which the present disclosure pertains having thebenefit of the teachings presented in the foregoing descriptions and theassociated drawings. Therefore, it is to be understood that the presentdisclosure is not to be limited to the specific examples illustrated andthat modifications and other examples are intended to be included withinthe scope of the appended claims. Moreover, although the foregoingdescription and the associated drawings describe examples of the presentdisclosure in the context of certain illustrative combinations ofelements and/or functions, it should be appreciated that differentcombinations of elements and/or functions may be provided by alternativeimplementations without departing from the scope of the appended claims.Accordingly, parenthetical reference numerals in the appended claims arepresented for illustrative purposes only and are not intended to limitthe scope of the claimed subject matter to the specific examplesprovided in the present disclosure.

The invention claimed is:
 1. A system for creating a feedstock line foradditive manufacturing of an object, the feedstock line having afeedstock-line length, the system comprising: a prepreg-tow supply,configured to dispense a precursor prepreg tow that comprises elongatefilaments and resin, covering the elongate filaments; a prepreg-towseparator, configured to separate the precursor prepreg tow, dispensedfrom the prepreg-tow supply, into individual ones of the elongatefilaments, at least partially covered with the resin, or into subsets ofthe elongate filaments, at least partially covered with the resin,wherein each of the subsets comprises a plurality of the elongatefilaments; a full-length-optical-waveguide supply, configured todispense at least one full-length optical waveguide; anoptical-direction-modifier supply, configured to dispense opticaldirection modifiers to be applied to the individual ones of the elongatefilaments, at least partially covered with the resin, or the subsets ofthe elongate filaments, at least partially covered with the resin,originating from the prepreg-tow separator, and wherein each of theoptical direction modifiers has an outer surface and each of the opticaldirection modifiers is configured such that when electromagneticradiation strikes the outer surface from a first direction, at least aportion of the electromagnetic radiation departs the outer surface in asecond direction that is at an angle to the first direction; a combiner,configured to combine the optical direction modifiers, the individualones of the elongate filaments, at least partially covered by the resin,originating from the prepreg-tow separator, and at least the onefull-length optical waveguide, dispensed by thefull-length-optical-waveguide supply, or the subsets of the elongatefilaments, at least partially covered by the resin, originating from theprepreg-tow separator, and at least the one full-length opticalwaveguide, dispensed by the full-length-optical-waveguide supply, into aderivative prepreg tow so that each of the elongate filaments and atleast the one full-length optical waveguide extend along all of thefeedstock-line length and at least the one full-length optical waveguideand the optical direction modifiers are interspersed among the elongatefilaments and at least partially covered by the resin; and at least oneheater, configured to heat at least one of: the resin in the precursorprepreg tow, dispensed from the prepreg-tow supply, to a first thresholdtemperature to facilitate separation of the precursor prepreg tow by theprepreg-tow separator into the individual ones of the elongate filamentsor into the subsets of the elongate filaments; the resin that at leastpartially covers the individual ones of the elongate filaments or thesubsets of the elongate filaments, originating from the prepreg-towseparator, to a second threshold temperature to cause wet-out of atleast the one full-length optical waveguide and the individual ones ofthe elongate filaments or of at least the one full-length opticalwaveguide and the subsets of the elongate filaments in the derivativeprepreg tow by the resin; or the resin that at least partially coversthe elongate filaments in the derivative prepreg tow, originating fromthe combiner, to a third threshold temperature to cause wet-out of atleast the one full-length optical waveguide and the elongate filamentsin the derivative prepreg tow by the resin.
 2. The system according toclaim 1, wherein the elongate filaments are opaque to electromagneticradiation.
 3. The system according to claim 1, wherein: at least the onefull-length optical waveguide comprises a full-length optical core; thefull-length optical core comprises a first full-length-optical-core endface, a second full-length-optical-core end face, opposite the firstfull-length-optical-core end face, and a full-length peripheral surface,extending between the first full-length-optical-core end face and thesecond full-length-optical-core end face; and at least the onefull-length optical waveguide is configured such that whenelectromagnetic radiation enters the full-length optical core via atleast one of the first full-length-optical-core end face, the secondfull-length-optical-core end face, or the full-length peripheralsurface, at least a portion of the electromagnetic radiation exits thefull-length optical core via the full-length peripheral surface.
 4. Thesystem according to claim 3, wherein at least the one full-lengthoptical waveguide is configured such that when the electromagneticradiation enters the first full-length-optical-core end face of thefull-length optical core, an initial portion of the electromagneticradiation exits the full-length optical core via the full-lengthperipheral surface and a final portion of the electromagnetic radiation,remaining in the full-length optical core after the initial portion ofthe electromagnetic radiation exits the full-length optical core, exitsthe full-length optical core via the second full-length-optical-core endface.
 5. The system according to claim 3, wherein: the full-lengthoptical core has a full-length-optical-core refractive index; at leastthe one full-length optical waveguide further comprises afull-length-optical-core cladding, at least partially covering thefull-length optical core; the full-length-optical-core claddingcomprises at least a first full-length-optical-core cladding resin,having a full-length-optical-core first-cladding-resin refractive index;the full-length-optical-core cladding is non-uniform along at least theone full-length optical waveguide; and the full-length-optical-corerefractive index is greater than the full-length-optical-corefirst-cladding-resin refractive index.
 6. The system according to claim5, wherein: the full-length peripheral surface hasfull-length-peripheral-surface regions devoid of the firstfull-length-optical-core cladding resin; the full-length-optical-corecladding further comprises a second full-length-optical-core claddingresin, having a full-length-optical-core second-cladding-resinrefractive index; the second full-length-optical-core cladding resincovers the full-length-peripheral-surface regions of the full-lengthperipheral surface; and the full-length-optical-coresecond-cladding-resin refractive index is greater than thefull-length-optical-core first-cladding-resin refractive index.
 7. Thesystem according to claim 6, wherein the second full-length-optical-corecladding resin also covers the first full-length-optical-core claddingresin.
 8. The system according to claim 6, wherein: the resin has aresin refractive index; and the resin refractive index is greater thanthe full-length-optical-core second-cladding-resin refractive index. 9.The system according to claim 3, wherein the full-length peripheralsurface has a surface roughness that is selected such that whenelectromagnetic radiation enters the full-length optical core via atleast one of the first full-length-optical-core end face, the secondfull-length-optical-core end face, or the full-length peripheralsurface, at least a portion of the electromagnetic radiation exits thefull-length optical core via the full-length peripheral surface.
 10. Thesystem according to claim 9, wherein at least the one full-lengthoptical waveguide is devoid of any cladding that covers the full-lengthoptical core.
 11. The system according to claim 1, further comprising: aresin supply, configured to provide additional resin to be applied to atleast one of the precursor prepreg tow, dispensed from the prepreg-towsupply, the individual ones of the elongate filaments, at leastpartially covered with the resin, or the subsets of the elongatefilaments, at least partially covered with the resin, originating fromthe prepreg-tow separator, at least the one full-length opticalwaveguide, dispensed from the full-length-optical-waveguide supply, orthe derivative prepreg tow, originating from the combiner, such that theelongate filaments and at least the one full-length optical waveguide inthe derivative prepreg tow are covered with the resin and the additionalresin.
 12. The system according to claim 11, wherein: the prepreg-towseparator is configured to impart a first electrical charge to theelongate filaments or to the resin as the precursor prepreg tow isseparated into the individual ones of the elongate filaments, at leastpartially covered with the resin, or into the subsets of the elongatefilaments, at least partially covered with the resin; the resin supplyis configured to impart a second electrical charge to the additionalresin when the additional resin is applied to at least one of theindividual ones of the elongate filaments, at least partially covered bythe resin, or the subsets of the elongate filaments, at least partiallycovered by the resin and originating from the prepreg-tow separator, orthe derivative prepreg tow, originating from the combiner, such that theelongate filaments and at least the one full-length optical waveguide inthe derivative prepreg tow are covered with the resin and the additionalresin; and the second electrical charge and the first electrical chargehave opposite signs.
 13. The system according to claim 1, wherein thecombiner is configured to at least one of twist, weave, or braid theindividual ones of the elongate filaments and at least the onefull-length optical waveguide, dispensed by thefull-length-optical-waveguide supply, or the subsets of the elongatefilaments, originating from the prepreg-tow separator, and at least theone full-length optical waveguide, dispensed by thefull-length-optical-waveguide supply, into the derivative prepreg tow.14. The system according to claim 1, wherein: the optical directionmodifiers comprise partial-length optical waveguides; each of thepartial-length optical waveguides comprises a partial-length opticalcore; the partial-length optical core of each of the partial-lengthoptical waveguides comprises a first partial-length-optical-core endface, a second partial-length-optical-core end face, opposite the firstpartial-length-optical-core end face, and a partial-length peripheralsurface, extending between the first partial-length-optical-core endface and the second partial-length-optical-core end face; and each ofthe partial-length optical waveguides is configured such that when theelectromagnetic radiation enters the partial-length optical core via atleast one of the first partial-length-optical-core end face, the secondpartial-length-optical-core end face, or the partial-length peripheralsurface, at least a portion of the electromagnetic radiation exits thepartial-length optical core via the partial-length peripheral surface.15. The system according to claim 1, wherein: the optical directionmodifiers comprise optical direction-modifying particles; and theoptical direction-modifying particles are configured to at least one ofreflect, refract, diffract, or Rayleigh-scatter the electromagneticradiation, incident on the outer surface of any one of the opticaldirection-modifying particles to disperse the electromagnetic radiation.16. The system according to claim 15, wherein: each of the elongatefilaments has a minimum outer dimension; and each of the opticaldirection-modifying particles has a maximum outer dimension that is lessthan one-eighth the minimum outer dimension of any one of the elongatefilaments.
 17. The system according to claim 15, wherein each of theoptical direction-modifying particles has a minimum outer dimension thatis greater than or equal to 50 nm.
 18. The system according to claim 1,further comprising: a resin supply, configured to provide additionalresin to be applied to at least one of the precursor prepreg tow,dispensed from the prepreg-tow supply, the individual ones of theelongate filaments, at least partially covered with the resin, or thesubsets of the elongate filaments, at least partially covered with theresin, originating from the prepreg-tow separator, at least the onefull-length optical waveguide, dispensed from thefull-length-optical-waveguide supply, or the derivative prepreg tow,originating from the combiner, such that the elongate filaments and atleast the one full-length optical waveguide in the derivative prepregtow are covered with the resin and the additional resin; and wherein theoptical-direction-modifier supply and the resin supply together form acombined supply, configured to dispense the optical direction modifierstogether with the additional resin.
 19. A method of creating a feedstockline for additive manufacturing of an object, the feedstock line havinga feedstock-line length, the method comprising steps of: separating aprecursor prepreg tow, comprising elongate filaments and resin, coveringthe elongate filaments, into individual ones of the elongate filaments,at least partially covered with the resin, or into subsets of theelongate filaments, at least partially covered with the resin, whereineach of the subsets comprises a plurality of the elongate filaments;applying optical direction modifiers to the individual ones of theelongate filaments, at least partially covered with the resin, or to thesubsets of the elongate filaments, at least partially covered with theresin, and wherein each of the optical direction modifiers has an outersurface and each of the optical direction modifiers is configured suchthat when electromagnetic radiation strikes the outer surface from afirst direction, at least a portion of the electromagnetic radiationdeparts the outer surface in a second direction that is at an angle tothe first direction; combining the individual ones of the elongatefilaments, at least partially covered with the resin, the opticaldirection modifiers, and at least one full-length optical waveguide orthe subsets of the elongate filaments, at least partially covered withthe resin, the optical direction modifiers, and at least the onefull-length optical waveguide into a derivative prepreg tow so that eachof the elongate filaments and at least the one full-length opticalwaveguide extend along all of the feedstock-line length and at least theone full-length optical waveguide and the optical direction modifiersare interspersed among the elongate filaments; and heating at least oneof: the resin in the precursor prepreg tow prior to separating theprecursor prepreg tow into the individual ones of the elongatefilaments, at least partially covered with the resin, or into thesubsets of the elongate filaments, at least partially covered with theresin, to a first threshold temperature to facilitate separating theprecursor prepreg tow; the resin, at least partially covering theindividual ones of the elongate filaments or the subsets of the elongatefilaments following separating the precursor prepreg tow into theindividual ones of the elongate filaments, at least partially coveredwith the resin, or into the subsets of the elongate filaments, at leastpartially covered with the resin, and prior to combining the individualones of the elongate filaments, at least partially covered with theresin, and at least the one full-length optical waveguide or the subsetsof the elongate filaments, at least partially covered with the resin,and at least the one full-length optical waveguide into the derivativeprepreg tow, to a second threshold temperature to cause wet-out of atleast the one full-length optical waveguide and the elongate filamentsin the derivative prepreg tow by the resin; or the resin, at leastpartially covering the elongate filaments in the derivative prepreg tow,to a third threshold temperature to cause wet-out of at least the onefull-length optical waveguide and the elongate filaments in the derivateprepreg tow by the resin.
 20. The method according to claim 19, wherein:at least the one full-length optical waveguide comprises a full-lengthoptical core; the full-length optical core comprises a firstfull-length-optical-core end face, a second full-length-optical-core endface, opposite the first full-length-optical-core end face, and afull-length peripheral surface, extending between the firstfull-length-optical-core end face and the secondfull-length-optical-core end face; and at least the one full-lengthoptical waveguide is configured such that when electromagnetic radiationenters the full-length optical core via at least one of the firstfull-length-optical-core end face, the second full-length-optical-coreend face, or the full-length peripheral surface, at least a portion ofthe electromagnetic radiation exits the full-length optical core via thefull-length peripheral surface.
 21. The method according to claim 20,wherein at least the one full-length optical waveguide is configuredsuch that when the electromagnetic radiation enters the firstfull-length-optical-core end face of the full-length optical core, aninitial portion of the electromagnetic radiation exits the full-lengthoptical core via the full-length peripheral surface and a final portionof the electromagnetic radiation, remaining in the full-length opticalcore after the initial portion of the electromagnetic radiation exitsthe full-length optical core, exits the full-length optical core via thesecond full-length-optical-core end face.
 22. The method according toclaim 21, wherein at least the one full-length optical waveguide isconfigured such that the initial portion of the electromagneticradiation, which exits the full-length optical core via the full-lengthperipheral surface, is greater than or equal to the final portion of theelectromagnetic radiation, which exits the full-length optical core viathe second full-length-optical-core end face.
 23. The method accordingto claim 20, wherein: the full-length optical core has afull-length-optical-core refractive index; at least the one full-lengthoptical waveguide further comprises a full-length-optical-core cladding,at least partially covering the full-length optical core; thefull-length-optical-core cladding comprises at least a firstfull-length-optical-core cladding resin, having afull-length-optical-core first-cladding-resin refractive index; thefull-length-optical-core cladding is non-uniform along at least the onefull-length optical waveguide; and the full-length-optical-corerefractive index is greater than the full-length-optical-corefirst-cladding-resin refractive index.
 24. The method according to claim23, wherein: the full-length peripheral surface hasfull-length-peripheral-surface regions devoid of the firstfull-length-optical-core cladding resin; the full-length-optical-corecladding further comprises a second full-length-optical-core claddingresin, having a full-length-optical-core second-cladding-resinrefractive index; the second full-length-optical-core cladding resincovers the full-length-peripheral-surface regions of the full-lengthperipheral surface; and the full-length-optical-coresecond-cladding-resin refractive index is greater than thefull-length-optical-core first-cladding-resin refractive index.
 25. Themethod according to claim 24, wherein the secondfull-length-optical-core cladding resin also covers the firstfull-length-optical-core cladding resin.
 26. The method according toclaim 24, wherein: the resin has a resin refractive index; and the resinrefractive index is greater than the full-length-optical-coresecond-cladding-resin refractive index.
 27. The method according toclaim 20, wherein the full-length peripheral surface has a surfaceroughness that is selected such that when electromagnetic radiationenters the full-length optical core via at least one of the firstfull-length-optical-core end face, the second full-length-optical-coreend face, or the full-length peripheral surface, at least a portion ofthe electromagnetic radiation exits the full-length optical core via thefull-length peripheral surface.
 28. The method according to claim 27,wherein at least the one full-length optical waveguide is devoid of anycladding that covers the full-length optical core.
 29. The methodaccording to claim 19, further comprising a step of: applying anadditional resin to cover the elongate filaments and at least the onefull-length optical waveguide such that the elongate filaments and atleast the one full-length optical waveguide are covered by the resin andthe additional resin in the derivative prepreg tow.
 30. The methodaccording to claim 29, wherein the additional resin is applied to coverthe elongate filaments and at least the one full-length opticalwaveguide, such that the elongate filaments and at least the onefull-length optical waveguide are covered by the resin and theadditional resin in the derivative prepreg tow, at least one of beforeor after separating the precursor prepreg tow into the individual onesof the elongate filaments, at least partially covered with the resin, orinto the subsets of the elongate filaments, at least partially coveredwith the resin.
 31. The method according to claim 29, wherein theadditional resin is applied to cover the elongate filaments and at leastthe one full-length optical waveguide, such that the elongate filamentsand at least the one full-length optical waveguide are covered by theresin and the additional resin in the derivative prepreg tow, at leastone of before or after combining the individual ones of the elongatefilaments, at least partially covered with the resin, or the subsets ofthe elongate filaments, at least partially covered with the resin, andat least the one full-length optical waveguide into the derivativeprepreg tow.
 32. The method according to claim 29, wherein: the step ofseparating the precursor prepreg tow into individual ones of theelongate filaments, at least partially covered with the resin, or intosubsets of the elongate filaments, at least partially covered with theresin, comprises imparting a first electrical charge to the elongatefilaments or to the resin; the step of applying the additional resin tocover the elongate filaments and at least the one full-length opticalwaveguide, such that the elongate filaments and at least the onefull-length optical waveguide are covered by the resin and theadditional resin in the derivative prepreg tow, comprises imparting asecond electrical charge to the additional resin; and the secondelectrical charge and the first electrical charge have opposite signs.33. The method according to claim 19, wherein the step of combining theindividual ones of the elongate filaments, at least partially coveredwith the resin, and at least the one full-length optical waveguide orthe subsets of the elongate filaments, at least partially covered withthe resin, and at least the one full-length optical waveguide into thederivative prepreg tow comprises at least one of twisting, weaving, orbraiding the individual ones of the elongate filaments, at leastpartially covered with the resin, and at least the one full-lengthoptical waveguide, or the subsets of the elongate filaments, at leastpartially covered with the resin, and at least the one full-lengthoptical waveguide, into the derivative prepreg tow.
 34. The methodaccording to claim 19, wherein: the optical direction modifiers comprisepartial-length optical waveguides; each of the partial-length opticalwaveguides comprises a partial-length optical core; the partial-lengthoptical core of each of the partial-length optical waveguides comprisesa first partial-length-optical-core end face, a secondpartial-length-optical-core end face, opposite the firstpartial-length-optical-core end face, and a partial-length peripheralsurface, extending between the first partial-length-optical-core endface and the second partial-length-optical-core end face; and each ofthe partial-length optical waveguides is configured such that when theelectromagnetic radiation enters the partial-length optical core via atleast one of the first partial-length-optical-core end face, the secondpartial-length-optical-core end face, or the partial-length peripheralsurface, at least a portion of the electromagnetic radiation exits thepartial-length optical core via the partial-length peripheral surface.35. The method according to claim 19, wherein: the optical directionmodifiers comprise optical direction-modifying particles; and theoptical direction-modifying particles are configured to at least one ofreflect, refract, diffract, or Rayleigh-scatter the electromagneticradiation, incident on the outer surface of any one of the opticaldirection-modifying particles, to disperse the electromagneticradiation.
 36. The method according to claim 35, wherein: each of theelongate filaments has a minimum outer dimension; and each of theoptical direction-modifying particles has a maximum outer dimension thatis less than one-eighth the minimum outer dimension of any one of theelongate filaments.
 37. The method according to claim 35, wherein eachof the optical direction-modifying particles has a maximum outerdimension that is less than 1000 nm.
 38. The method according to claim35, wherein each of the optical direction-modifying particles has aminimum outer dimension that is greater than or equal to 50 nm.
 39. Themethod according to claim 35, wherein in the feedstock line, the opticaldirection-modifying particles comprise less than 10% by weight of theresin.
 40. The system according to claim 3, wherein thefull-length-optical-waveguide supply comprises at least the onefull-length optical waveguide.